This WebChat was co-hosted with the Discovery Channel.
This transcript is unedited; proceed at your own risk.

Participants from Galileo:
Jim Erickson (Jimericksonsso)
Marcia Segura (Marcia_nims)
Todd Barber (Toddrocketenginr)
Dan Erickson (Dan_erickson_cds)
Nancy Vandermeer (Nancy_seq_sys)
Stuart Stephens (Stuart_stephens_uvs-euv)
John McKinney (Johnm_ground_sys )
Matthew Fishburn (Matthew_ssi)
Leslie Lowes (Leslie_outreach_lead)
Gerry Snyder (Ggerry_snyder)
Jo Pitesky (Jopiteskygll)
Lou D'Amario (Navdep)
Jim Taylor (Galileo_radio)
Randy Herrera (Randy_radsci>
Cynthia Phillips (cynthia_imaging)
Randy Tufts (europaphile)
Leo Cheng (Leo_cheng)
Robert Sullivan (Rob_galileo_ssi)

Guest54 says, "Hi there, I'm Gaby, Would you tell us what happened to the probe that entered Jupiter's atmosphere?"

Dan_erickson_cds says, "The probe was vaporize, crushed, and irradiated."

Guest54 says, "why the moon Europa was called Europa?"

Chat says, "Welcome all!  I'm the Science Editor at Discovery Channel Online. We're glad you're here today!"

Toddrocketenginr says, "Anyone out there on GLL experts on mythology?  Europa was one of Jupiter's lovers, I believe."

Marcia_nims says, "Europa was a princess carried off by Zeus, another name for Jupiter.  This is the G rated version of the story."

Ggerry-snyder says, "Europa was sister of Cadmus, abducted by Zeus (Jupiter)"

Qix says, "can anyone tell me the names of the people whoare involved in the galileo project who is here right now?"

Marcia_nims says, "Marcia Segura, Near Infrared Mapping Spectrometer science coordinator"

Nancy_seq_sys says, "HI QIX - My name is Nancy, I work on the Sequence team"

Jopiteskygll says, "hi Qix, my name is Jo Pitesky, I work on outreach"

Navdep says, "Lou D'Amario, Galileo Navigation Deputy Team Chief"

Johnm_ground_sys says, "John McKinney:  Galileo Ground System Engineering"

Ggerry-snyder says, "I am Gerry Snyder. I write requirements for and test flight software."

Guest54 says, "What is the composition of the liquid below the iced surface of Europa?"

Jimericksonsso says, "Hi qix - My name is Jim and I work on managing the Science and sequence end of things"

Qix says, "will all of you be here in the afternoon"

Marcia_nims says, "Hi Qix, we've revealed our identity...  What about you?"

Marcia_nims says, "I'll be here for all hours"

Jopiteskygll says, "Qix, some of us will be here this afternoon, some of us won't, and there will be some new folk as well."

Matthew_ssi says, "Matthew Fishburn here.  I'm with the SSI (camera) team and I also write the Galileo SEPO webpage."

Qix says, "my name is Linus, and I'm just a student"

Windsong says, "I have a question, does any schools set up chats with you guys?"

Dan_erickson_cds says, "Dan Erickson - CDS Flight Software"

Windsong says, "This would be a wonderful way to extend science class and keep children interested."

Qix says, "say bye I hope to speak with some of you this afternoon"

Johnm_ground_sys says, "qix/linus:  Not "just" a student I'll bet;  but an excellent one to show such interest in the space program"

Guest65 says, "What was the total cost of the entire Galeleio project?"

Marcia_nims says, "Guest54, The composition of Europa's subsurface is still an unanswered question."

Guest69 says, "i'm in school so i guess they do windsong"

Dan_erickson_cds says, "Windsong, the Galileo home page http://www.jpl.nasa.gov/galileo can lead you to a number of resources which can be used in the classroom."

Toddrocketenginr says, "Guest 69, not much yet.  Do you have any questions for the GLL team?"

Windsong says, "Guest 69, You;re at school now?"

Windsong says, "Thanks you Dan I will check it out and give it to my sons science teacher"

Leslie_outreach says, ""Windsong, we always want to help out education.  Are you aware of our "Online From Jupiter program?""

Marcia_nims says, "The total cost of the Galileo project I believe has been on the order of 25 - 30 cents for each person in the U.S. per year.  Jo correct me if I'm off the mark."

Windsong says, "Leslie, no I just found out about this program today."

Jopiteskygll says, "Guest65, the total cost of the project (from the very start, long long long before launch) to the end of the mission is in the range of $1.4 billion.  Like Marcia says, it works out to 25 cents per person per year. So it's not as expensive as it seems; the project has been running for some 20 years!"
Chat says, "I have a question -- what was the reaction in the team when then latest pictures came across -- 100x better than before."

Leslie_outreach says, "Windsong, how did you learn about this?  Do you know about the Galileo Web Page?"

Windsong says, "My sons school use to have Distance learning but I haven't heard if they have it anymore"

Windsong says, "Leslie, I'm addicted to the Discovery Channel what can I tell you???"


Nancy_seq_sys says, "I've been thrilled with all the pictures and other science results so far!"


Marcia_nims says, "When new images or other data arrive from Galileo, it's always exciting.  Much like Christmas morning for a 5 year old."


Guest65 says, "What is the current position of the satellite?"

Ggerry-snyder says, "The team's reaction is very much like a child on Christmas morning. We don't know what we will find, but we do know it will be something wonderful."

Guest66 says, "lQuestion about getting into light speed: If our space ship has unlimited  thrust"

Toddrocketenginr says, "Chat, I can say as a non-scientist that I was floored and the 1st thing I thought was, "Wow, Europa is like a fractal!" (self similar on all scales)"

Nancy_seq_sys says, "Currently Galileo is heading away from Jupiter, our next encounter is with Europa at the end of February"

Guest66 says, "and our speed is 30,000 mph"

Windsong says, "Leslie, no I 'm not familar with the Galileo web page"

Leslie_outreach says, "windsong, that's great!  We are running an educational event on the web  about Galileo starting the end of February and running through March.  Its a great way to participate and learn about Galileo.  I'll let Jo tel"

Dan_erickson_cds says, "Jupiter is on the far side of the Sun from Earth right now. That is why we can't talk to Galileo at this time."


Leslie_outreach says, "windsong, continued:  I'll let Jo tell you more since she's running the event."


Guest72 says, "hi, I have looked at some of the stats on the moons at Jupiter, and I was wondering how you came to the conclusion that some of the moons are composed of water."

Jopiteskygll says, "windsong, Leslie is talking about a project called "Online From Jupiter," where people working on the project write journals and bios, and answer questions from students.  Plus, there are some activities (e.g. a photo contest, learning about why scientists are so intersted in studying Europa, and so forth).  Take a look at the last one at http://quest.arc.nasa.gov/jupiter.html"

Galileo_radio says, "Hi, all!  It looks like this Galileo chat is already very busy.  I'm Jim Taylor, calling myself Galileo-Radio.  I deal with the radio communications links between the spacecraft and the Deep Space Stations here on earth."


Party says, "How can I get pictures on galileos's images"

Guest65 says, "What is the most suprising information gathered during this mission"


Marcia_nims says, "Party, you can download them from the Galileo Homepage."


Nancy_seq_sys says, "Ganymede's magnetosphere was a surprise"



Jopiteskygll says, "Party, say Guest66, about your question about light speed and Galileo: Galileo doesn't have unlimited thrust, because it doesn't have an unlimited supply of propellant."


Party says, "Is there a role for people with medical degrees at nasa and how can I find out more ?"


Dan_erickson_cds says, "Guest72, I believe that was determined by looking at the spectrum of the light coming back from the moons."


Windsong says, "Thanks for all the great info, I am writing down all the urls to give to the science teacher"

Guest66 says, "Question: If our spaceship has unlimited thrust ans going 30,000 mph is it possible to attain the speed of light by simply adding another 30,000 mph etc until the speed of light has been reached."

Windsong says, "is there any newsletters connected with this program?"

Guest71 says, "Hello Jim Taylor,  what do you mean by the "Deep Space Stations?""

Galileo_radio says, "Party, you asked about NASA opportunities for people with medical degrees.  The most obvious arfea I can think of is the Manned space program.  Haven't there been Physician astronauts.  Check out the NASA Johnson Center home page."



Ggerry-snyder says, "The density (computed from radius and mass) gives the amount of rock and the amount of ice."


Guest76 says, "What is the most surprising information gathered during this mission?iss"


Dan_erickson_cds says, "Guest72 continued: Of course spectra only show that the surface of the moon is largely water. When we fly by, we carefully track the change in Galileos orbit caused by the moon's gravity. This lets us determine the density of the layers of material inside."



Jopiteskygll says, "Windsong, there's the Galileo Messenger, and there's also now a new status e-mail list.  Look for info on both of these on the Galileo home page."



Toddrocketenginr says, "Guest 66, that's a good question!  TThe answer is "no" because your mass would become infinite as you approached the speed of light!"


Party says, "what exactly happened to the probe that was sent into jupiters atmosphere ?"



Galileo_radio says, "Guest 71, there are three sites where we have large ground antennas for communicating with spacecraft out beyond the moon -- thus "Deep Space".  These stations are near Canberra in Australia, near Madrid in Spain, and out in the California desert about 200 miles (320 km) northeast of Los Angeles.  The antennas are as big as 70 meters in diameter."



Windsong says, "Thanks you guys are great."


Party says, "Did you receive any information from it that has altered your preconceptions about jupiterr or did the data just reinforce your already held views on jupiter ?"


Guest72 says, "is is possible to land a probe on Io?"

Jopiteskygll says, "Party, the probe was completely vaporized by 10 hours after the end of its mission.  It still amazes me to think about vaporizing titanium and aluminum!"



Guest71 says, "Can the "thickness" of the lubricating water under Europa's ice surface be determined?"


Galileo_radio says, "Party, as the Probe descended, it encountered great pressures and temperatures.  Eventually, the temperature exceeded the decomposition point of all or most molecules.  I understand the Probe is now onlyh isolated atoms of its original material.  Dust to dust... gas to gas...  There was a "Probe Crush" series on the last "On Line from Jupiter".  Maybe Jo can give you the URL for more info."



Randy_radsci enters.



Party says, "jopiteskygll was it vaporized due to atmospheric pressure or descent speed and resulting friction ?"



Toddrocketenginr says, "Party, the probe was vaporized in Jupiter's atmosphere and the atoms that made up the probe are now part of Jupiter's atmosphere!  Kind of eerie, no?"



Leslie_outreach says, "party: we recently found that Ganymede, Jupiter (and the solar system)'s largest moon, has its own magnetic field, similar to the earth.  Its the only moon known to have a magnetic field.  That was totally unexpected!"


Ggerry-snyder says, "An Io lander would be possible, but with the radiation level there it would not last long."


Dan_erickson_cds says, "Gerry, maybe we could find a protected spot on IO."

Guest72 says, "where would the radiation come from"


Party says, "why do certain planets have magnetic fields and others not ? I mean doesn't the magnetic field partly protect the planet from ionizing radiation and would;nt that have implications when looking for planets with possible traces of life ? Does mars or d"


Jopiteskygll says, "Party, it was vaporized due to the increasing heat and pressure.  There's a paper on this at http://www.transatlantech.com/tps/hot-top-galileo-galprobe.html"


Guest66 says, "If Estein was wrong  would it then be possible to attain light speed by the method  I reffered to? FOR ; TODDROCKETENGINR"

Stuart_s_uvs-euv says, "say In general, I think some of the level of detail we've seen on the satellite surfaces is unexpected.  For example, the variety of features on Europa couldn't be anticipated, and any preconceptions that folks had have undoubtedly been proben to be wrong in some way.  People working on the satellite data can comment more on that....  (I work on the UV Spectrometer team)"

Leslie_outreach says, "General Question:  Did anyone enter this chat via the Galileo Home Page this morning?"



Toddrocketenginr says, "Yes, Guess 66, but that is a HUGE if, since many tests have now been performed that corroborate relativity...."

Ggerry-snyder says, "Yes, a magnetic field does help make life possible."

Party says, "leslie Yes I found the telnet address through it and then entered , why ?"

Rracer says, "Yes we did"

Dan_erickson_cds says, "Guest72 - The radiation around Jupiter consists mostly of charged particles bouncing around and being accelerated by JupiterÕs large magnetic field."

Leslie_outreach says, ""party, I just wanted to make sure we had our audience, as well as the Discovery OnLine followers.  Thanks!"

Marcia_nims says, "Stuart, I agree with you about Europa's level of surface detail.  But getting a plug in for Callisto.  The lack of surface detail was unexpected."

Party says, "I realise the main antenna is not working and all data is being transmitted and received by the small one how seriously has this hindered the operation , I mean recently it seems that everything is going close to plan but would the larger antenna have"

Stuart_s_uvs-euv says, "Thanks for the reminder, Marcia.  Sorry to say, I forgot about Callisto again!"

Toddrocketenginr says, "Frozen, where do you hail from?"

Party says, "Can I work at jpl over the summer or where can I apply to work there as a student ?"

Jopiteskygll says, "Todd, that was a truly awful pun"

Ggerry-snyder says, "Because of the reduced amount of data, things like movies of Jupiter's swirling atmosphere are not being made."



Guest72 says, "are there any future plans to send probes robes to the moons for samples?"


Guest67 says, "Will the remaining 3-4 images from the Nov. 6 Europa flyby (C3) be revealed soon. This was the most interesting image yet."

Toddrocketenginr says, "Jo, totally unintended...but I'll take it to honor former fellow Kansas Clyde Tombaugh, may he rest in peace...."

Leslie_outreach says, "Guest72, such plans to Europa are being looked at, including a lander to melt through the ice and then swim in the ocean we think could be underneath.  Nothing as yet has been funded."


Jopiteskygll says, "Party, there are some programs to work at jpl over the summer or as an intern.  They are for high school juniors and seniors and college students.  I don't know what address to write to;  look at http://www.jpl.nasa.gov/faq/#int for more info"

Guest66 says, "Question: How much energy does Jupiter produce for it's moons compared to the sun and earth?"

Nancy_seq_sys says, "The Europa Clipper was going to smash into the surface to throw debris into space, where an aerogel return craft would then sample it similar to a future comet mission"

Dan_erickson_cds says, "With the High-gain antenna, we could have transmitted 134,000 bits per second. The best we can do now is 160 bits per second. So with the larger antenna we could have received many more images. However, by recording data and playing it back slowly, and by carefully choosing which data to send to Earth, we can get most of the science value. Of course, we canÕt tell what we might be missing."

Frozen says, "Just entering and enjoying the chat.  We're from Three Lakes Elementary in Three Lakes, WI"

Toddrocketenginr says, "The main thing lost with the failure to deploy of the high gain antenna are the nifty Jupiter rotation movies...."

Guest72 says, "why does it seem that Europa is being focused on a bit more than the others?"

Frozen says, "We're interested if Galileo has found out anything concerning the source of Jupiter's surface lightning?"

Dan_erickson_cds says, "Because Europa may have liquid water or slushy ice, it may be a better candidate for recent or current life."

Jopiteskygll says, " ...and even though we lost the movies (which show the dynamics of how Jupiter's clouds move), we don't lose a lot of the science.  As anyone who's downloaded video clips off the web knows, animation is bandwidth-hungry"

Marcia_nims says, "Guest72.  It seems that way right now because the last orbit and the upcoming orbit are Europa targeted.  Ganymede will take the spotlight shortly and Callisto (my favorite) will follow."

Stuart_s_uvs-euv says, "In response to Guest72, there is certainly a lot of interest in the other Galilean satellites (ask Marcia about Callisto...).  For example, Io would be the focus of high resolution imaging, but we don't want to repeatedly get in close to Jupiter (4 orpiter radii or so) to look at it up close, because of all the Jovian radiation.  We plan on at least one close pass by Io late in the mission."


Guest72 says, "but doesn't Callisto and Ganymede supposedly have water too?"

Nancy_seq_sys says, "HELLO PARTICIPANTS - FEEL FREE TO ASK A GENERAL QUESTION OF THE GROUP, OR A QUESTION AIMED AT A SPECIFIC TEAM MEMBER"


Galileo_radio says, "Hi, Guests 92-96.  I'm Jim Taylor, working with the spacecraft radio, antennas, and data system.  The other end of our communication links with earth are the big dish antennas in California, Spain, and Australia."

Frozen says, "We asked about lightning on Jupiter, its causes..."

Guest72 says, "yes, why is Europa a better choice for colonization than Ganymede or Callisto?"


Marcia_nims says, "Guest72, Callisto's surface is 60 to 80% rocky or non-ice material.  We've discovered that some areas of Callisto's surface has cleaner ice than other areas.  Check out the Galileo homepage for a look at Asgard, one of Callisto's larger surface features."

Guest99 enters.

Dan_erickson_cds says, "Hello 99"

Dan_erickson_cds says, "I just had to get smart."

Guest66 says, "GALILEO RADIO: Question how does the energy output from Jupiter to it's moons compare to the energy the earth receives from the sun?"


Jopiteskygll says, "say Dan, yet another amazing pun from the Galileo side."


Leslie_outreach says, "Reminder to those who don't know:  Galileo home page is http://www.jpl.nasa.gov/galileo, and has new images from the spacecraft daily!"


Guest72 says, "when you say 'ice' do you mean frozen water, or frozen anythi"

Guest72 says, "anything else, like carbon dioxide?"

Galileo_radio says, "Frozen, I wish I could say more about your question on why Jupiter produces lightning. Maybe one of the atmospheric scientists could help.  I'll bet the way is similar to how it happens on earth.  You have to have an atmosphere that either has or produces charged particles.  The atmosphere has to separate the positives from the negatives in sufficient quantities.  Lightning is the "spark" when they get back together."


Toddrocketenginr says, "Frozen, I don't know a lot about the lightning, except that it is probably related to water clouds (?), was not detected near the probe, but was detected a few Earth diameters away from the probe.  Also there is about 10 times less lightning on Jupiter vs. Earth.  Comments from the more well informed?"

Guest89 says, "How far down under Europa ice floes does slushy ice/water start?  How deep does it go?"

Leslie_outreach says, "Guest72, its possible that sulphur from Io may be present in very small amounts on Europa's surface."

Dan_erickson_cds says, "Guest89 We don't know yet how thick the ice on Europa is or how thick the slush or water layer is. We are trying very hard to find out."



Marcia_nims says, "Guest72, frozen anything/water.  We're still trying to determine exactly what.  Analysis is ongoing"

Leslie_outreach says, "Guest89, we speculate 100-200 km of ice, and plan to narrow that number down over the course of Galileo's mission."

Guest89 says, "Dan, How are you trying.  What techniques?"

Dan_erickson_cds says, "Geuest89: Mstly two ways, careful study and measurement of the detailed images and gravity experiments."



Guest89 says, "Leslie, Can you help explain how you determined that estimate?"

Toddrocketenginr says, "A comment for all the science types on Galileo:  bravo!  I think the fact that there are very few engineering questions truly demonstrates that we are now a 1st-class science mission.  Of course, engineers are here to asnwer any questions..."

Dan_erickson_cds says, "Guest89: The features on the surface, such as recent ice flows and the character of the deformations of the ice will be matched against models of different thickness and composition."

Marcia_nims says, "How many schools do we have out there?"

Galileo_radio says, "Another way to look at the "science vs. engineering" questions, Toddrocket..., is that Galileo was an engineering mission for about the first seven years after launch.  Now the engineering takes a backseat to the science.  Even during those first seven years, we got marvelous science during the two flybys of Earth, the flyby of Venus, and the flybys of the two asteroids.  Have I left anything out of our "cruise mission"?"

Guest66 says, "STILL WAITING FOR ANSWER ABOUT ENERGY LEVELS!!!!"

Leslie_outreach says, ""Guest89, I'd like Mr Radio Science to confirm, but I believe that gravitational data gives us a rough estimate of the ice thickness, and then the resfigure from the behavior of the surface.""

Marcia_nims says, "Comet Shoemaker-Levy"



Dan_erickson_cds says, "Guest89: The gravity experiments from the flybys help us profile the different layers of density in the moon. These may be too slight to detect the boundary between ice and slush."



Toddrocketenginr says, "Galileo-radio--dont' forget Comet SL9!"



Jimericksonsso says, "yes we got to see the results of shoemaker levy hitting Jupiter"


Jopiteskygll says, "Guest66, I'm not clear on what you mean about energy levels of the moons; are you asking how much light Jupiter shines on its moons, as compared to how much shines on our own moon?"


Galileo_radio says, "Sorry, everyone, I was on vacation during Comet Shoemaker-Levy-9.  I'll never forget hearing the news reports about it as we were crossing over into Cape Cod."

Leslie_outreach says, ""marcia, can you ask Carlson about the energy from within Jupiter, compared to the sun, for Guest66?""



Guest119 says, "yeah thats what I said"



Guest119 says, "yeah thats what I said"



Dan_erickson_cds says, "Guest119 : Yeah, space is cool. And there is so much of it."



Guest119 says, "Can't you understand me?"


Leslie_outreach says, "Guest119, what do you like about space?  (welcome!)"


Galileo_radio says, "Guest 119, I like space, too.  I've never grown tired to learning more about it in my 35 years of working with satellites and spacecraft."


Guest119 says, "How do you know?"

Guest119 says, "It is big and full of surprises"


Marcia_nims says, "Leslie and Guest66, I'll investigate but won't have an answer until late today.  Guest66, please forward your e-mail address to msegura@jpluvs.jpl.nasa.gov"


Guest119 says, "You've been working with space for 35 years?"

Galileo_radio says, "Guest 119, I started with the RCA "Space Center" in New Jersey in 1962, working on the TIROS weather satellites they were making."

Galileo_radio says, "Hi, Rocket_ron.  What kind of rockets do you work with?"

Guest122 says, "What are the latest findings regarding the possibility of life on Europa?"

Guest66 says, "Checkk back with you later about answer to energy levels of Jupiter."

Guest89 says, "How did Galileo filter out the large effects of the magnetic field of Jupiter to determine that some of its moons had a field as well?"

Leslie_outreach says, "Guest122, We believe we have evidence that at one time, an ocean probably existed underneath Europa's icy surface.  We still can't tell if it exists at the present time.  However, if it does, conditions are possible to support life there..."

Toddrocketenginr says, "Guest 89, actuallly, by Ganymede, the moon's magnetic field disrupts Jupiter's field in a well-known way."

Leslie_outreach says, "Guest122, ...We need water, organics, and a heat source.  We think organics that may be there came from meteorites."



Toddrocketenginr says, "Guest 89, continued:  It is an inverse square thing--near Ganymede, its field dominates over Jupiter's much bigger intrinsic field."


Guest66 says, "Galileo radio Question: What is the size of Jupter's largest moon compared to the size of earth?"

Stuart_s_uvs-euv says, "Leslie, do you know if more than water, organics, and a heat source are necessary for life?  I am thinking that a stable environment may also be required."


Ggerry-snyder says, "The continued existence of liquid water implies thermal stability."

Guest128 says, "What organic molecules have been identified on Jupiter's moons?"


Leslie_outreach says, "Guest66, Ganymede is larger in diameter than the U.S. is across.  The earth is about 2 1/2 times larger across than Ganymede.  Ganymede is just larger than Mercury"

Merlin says, "I've heard  that they may do an extra mission at jupiter after this.  What would they do then and when will they get approval?"


Dan_erickson_cds says, "The Galileo Project is planning an extended mission called the Galileo Europa Mission (GEM) which is not yet funded. This mission would include several flybys of Europa and possibly end with a flyby of IO. Radiation or budgets might kill the mission before then."

Leslie_outreach says, "Guest128, I don't know the exact answer to this, but I can tell you that when telescopes on earth are used to observe Europa, contaminents in the ice are there.  Our observations with the NIMS instrument will identify some of them."


Galileo_radio says, "Merlin, you may have heard about the Galileo Extended Mission that we hope to do with our spacecraft.  It would last for two more years after the end of the main mission this December.  We would need to get funding for it."

Guest66 says, "MARCIA: Question: Please compare the ammount of energy, light and heat, that Jupiter gives to it's moons compared to the energy the earth receives from the sun"

Leslie_outreach says, "hello, any educators or students on board with us now?"

Toddrocketenginr says, "Merlin, could you be referring to the Europa Ice Clipper?  There is talk of a mission to fire a projectile at Europa and collect the explosive fragments in aerogel and return them to Earth!"

Lhms says, "yes, there are educators ans students on board.  Whee are you from?"

Marcia_nims says, "Guest66, based on a brief discussion with some of the Jupiter atmospheric scientists moments ago, their response to me was Jupiter's output to it's moons were about 1/25th that of the output from sun to earth.  Of course much time could be spent coming up with more accurate figures but I'm hoping this gives you the answer you're looking for."

Ggerry-snyder says, "Marcia, you're saying Jupiter's moons get as much heat/light from Jupiter as from the Sun?  Seems like a lot!"

Leslie_outreach says, "Hi Lhms.  I'm the Lead Outreach Coordinator for the Galileo project.  We were hoping to reach classrooms with our web chats, glad you're on!"

Guest128 says, "What other investigations are planned in this mission?"

Marcia_nims says, "No, Gerry 1/25th of the total that the SUN gives the Earth."

Ggerry-snyder says, "Jupiter's moons get 1/25 as much heat/light from the Sun as the Earth does."

Marcia_nims says, "Gerry, Jupiter provides it's moons 1/25th the amount that the Sun gives the earth."

Dan_erickson_cds says, "For our guests, a question: How many bytes of memory are in the computer you are using to participate in this chat? How many bytes would you guess are in the Command and Data Subsystem(CDS) on the spacecraft. (It has 6 computers.)"



Guest89 says, "Thank you to whomever organized this question and answer session.  This is great!  You deserve many pats on the back.  It would be great to have these sessions more often.  Many thanks!"



Galileo_radio says, "Gerry, that would be true just on the basis that Jupiter is about 5 times as far from the sun as the earth (and the moon) is.  As to the amount of heat/light Jupiter's moons get from Jupiter, that's trickier.  The inner moons would get proportionally more than the outer ones."



Leslie_outreach says, "Guest128, there are many things we are looking at with Jupiter's system.  In addition to investigating Europa's fascinating surface, we'll be looking to see if it has its own magnetic field (like Ganymede does), and in the next orbit, we'll look to see if it has an atmosphere..."



Jopiteskygll says, "Guest89, we have a chat maybe every 2 or 3 months; keep an eye on the Galileo home page for details."


Marcia_nims says, "Anyone from New England participating in this chat?"


Leslie_outreach says, "Guest128, we are also going to study Jupiter itself, looking at its aurora and lightning, and investigating the intricate patterns of the clouds to understand their movement and what drives them."

Guest66 says, "GALILEO RADIO: Question: IS there enough energy being emmited from Jupiter to support life of it's moons?"

Dan_erickson_cds says, "Guest66 There is additional energyy from tidal forces which may heat up the interior of the moons. Life similar to the life found near deep ocean vents on Earth could be sustained by volcanic heat."

Jopiteskygll says, "Guest66, the life near deep ocean vents that Dan is referring to are these truly disgusting-looking tube worms; they're deep enough in the ocean that there is effectively no visible light."

Toddrocketenginr says, "Frozen, how are the northern lights from your location?  Did you know that Jupiter also has an aurora related tcharged particles streaming down to its polar regions?"

Guest128 says, "Guest128 says, "What organic molecules have been identified on any of Jupiter's moons?"

Frozen says, "We've had too few nights to view the northern lights; but Comet Hale-Bopp is showing up nicely.  Has Galileo turned any attention to that event?"

Marcia_nims says, "Frozen,  all our attention has been focused on Jupiter and moons."

Guest66 says, "GALILEO RADO: Question; What does mettalic hydrogen that is found inside jupiter look like?"

Toddrocketenginr says, "Frozen, nope, Galileo has not looked at Hale-Bopp.  Our instruments are not designed to look at an object so far away.  Hubble will do a nice job, on the other hand."

Toddrocketenginr says, "Frozen, I should say I THINK Hubble will look at Hale-Bopp--not entirely sure.  Hubble can't look too close to the sun..."


Dan_erickson_cds says, "Any guesses? For our guests, a question: How many bytes of memory are in the computer you are using to participate in this chat? How many bytes would you guess are in the Command and Data Subsystem(CDS) on the spacecraft. (It has 6 computers.)"

Marcia_nims says, "Dan, I'll play straight man for you.  My computer has 32 meg."

Frozen says, "If you mean RAM, we have 8,000,000bytes.  CDS - 800,000,000bytes?"

Dan_erickson_cds says, "Frozen, yes RAM is what I mean. We have no disk. We store data on the taqpe recorder, but no programs."

Dan_erickson_cds says, "Frozens guess is too high, anybody want to take a second guess?"

Galileo_radio says, "Hi, all.  I'm Jim Taylor.  I had to leave the chat for a few minutes to work a radio issue.  We are planning for the 6th encounter of the Orbital mission.  Part of that has Jupiter's satellite Europa interrupting ("occulting") the radio signal from Galileo.  I had to figure out some details the tracking station will have to do for the occultation."


Dan_erickson_cds says, "So far, Frozen is closest, since his is the only guess. There is a prize!"

Marcia_nims says, "What's the prize?"

Leslie_outreach says, ""hello everyone.  I'd like to let you know that we have an electronic mailing list that you can join to get the latest news about Galileo.  Send an email to:  majordomo@sender.jpl.nasa.gov    and in the body of the message, put   subscribe galileo your-email-address   (substituting your actual email address).  Please join us!"

Frozen says, "Can we guess again?  How about 400meg."

Jimericksonsso says, "approval for the GEM is in process, and should happen during the summersay Dan, are hints appropriate?"

Marcia_nims says, "Frozen, I'd guess lower if I were you."

Dan_erickson_cds says, "Sure Jim, give 'em a hint. I'll repeat the question."

Frozen says, "Okay - how about 200Mb"

Dan_erickson_cds says, "For our guests, a question: How many bytes of memory are in the computer you are using to participate in this chat? How many bytes would you guess are in the Command and Data Subsystem(CDS) on the spacecraft. (It has 6 computers.)"



Guest143 says, "What organic molecules have been identified thus far?"



Galileo_radio says, "Marcia_nims, what's this contest that Frozen is doing well in?  Can Galileo people enter?  8-)"


Dan_erickson_cds says, "Frozen is much warmer."

Frozen says, "150Mb"

Marcia_nims says, "Frozen, I'd go even lower."

Dan_erickson_cds says, "You are hardening, Frozen."


Frozen says, "100mb"

Jimericksonsso says, "G'remember that the CDS was built (finished) in 1988."

Leslie_outreach says, "Marcia_nims and Guest143: Marcia, am I correct in stating that Galileo itself cannot measure organic materials, or can you see this in the infrared?"


Marcia_nims says, "The contest is how many bytes in CDS?  No, Jim Taylor, you can't participate but you can give hints."

Frozen says, "Most of us were 2 years old then.  How about 64Mb?"

Dan_erickson_cds says, "Anyone else want to guess. Some students or teachers maybe?"

Leslie_outreach says, "I remember the 1st PC I bought in 1981 had 640 kilobytes.  I bet that's closer!"

Guest66 says, "GALILEO RADIO: Question: What does the metalic hydrogen core of Jupiter look like to us? Does it look like steel etc.?"

Lj says, "64 kB?"

Galileo_radio says, "Right, Jimerickss.., the CDS *hardware* was finished before the 1989 Galileo launch, of course.  But they're always working on the software.  We are now using a major build installed last May, called "Phase 2".  This new software has data compression algorithms, a new signal coding scheme, and other goodies to make science gathering and transmission more efficient."

Marcia_nims says, "Leslie and Guest 143.  The Near Infrared Mapping Spectrometer can detect any material or mineral that has a spectral signature between 0.7 microns (almost visible) to 5.2 microns (thermal or temperature).  In fact, there was a paper written for Science after the Earth encounters by Galileo that stated NIMS had detected life on Earth (methane in rice paddies)"

Dan_erickson_cds says, "Guessing on CDS RAM size closes in i minute. Lj is closest so far."

Dan_erickson_cds says, "5 4 3 ..."

Dan_erickson_cds congratulates Lj and hands over a sparking, gilt-edged e-certificate good for bragging rights in any cantina in the galaxy.

Lj says, "8 kB?"

Dan_erickson_cds says, "Combined, all six Command and Data Subsystem computers have 384K bytes of memory.  Where a K is 1024 bytes. The computers were selected in the late Ô70s. The initial launch date was scheduled for 1982."

Dan_erickson_cds says, "64k was the closest guess."

Marcia_nims says, "Dan, Commodore 64 vintage.."

Toddrocketenginr says, " Guest 66, I don't really know what metallic H2 looks like.  I'd bet that it would NOT resemble familiar metals, since it is just solid hydrogen, after all (albeit at very high pressure)"

Dan_erickson_cds says, "Incidentally, A full image takes 640,000 bytes (800x800)"

Galileo_radio says, "Tell them how you get a full image (640K bytes) into a 300+K byte computer?"

Jimericksonsso says, "Todd - I might take that bet."

Dan_erickson_cds says, "Fortunately, the image can be held by the charge-coupled devices(CCD) in the imagining subsystem while we read it out and store it to the tape a line at a time."

Marcia_nims says, "Hi Images"

Jimericksonsso says, "so Dan it means that the camera has about the same storage as the whole CDS and AACS?"

Dan_erickson_cds says, "Data from the Near-Infrared Mapping Spectrometer can be voluminous as well. Care to comment Marcia?"

Dan_erickson_cds says, "The camera has more storage than the AACS and CDS combined, but it is a different type. The CCD storage degrades easily if it gets hit by changed particles from Jupiter's radiation."

Dan_erickson_cds says, "The closer we are to Jupiter, the more intense the radiation. At Europa, we have to read the image out of the camera within 15 seconds, or it is too corrupted by the radiation."



Lj says, "If someone can answer, when was NIMS image of Ganymede (released October 28, 1996) taken G1 or G2?"

Marcia_nims says, "You're right Dan, each wavelength NIMS takes (it  can take up to 408) in a field of view (it takes many to make a NIMS image) costs 25 bytes.  NIMS sometimes takes more than 100 fields of view in an observation."


Marcia_nims says, "Lj, The NIMS image of Ganymede was taken during G2."

Guest89 says, "Dan, Epoch Networks in Irvine, CA.  I am going to get in trouble if my boss sees here, so I am sneaking a peek every once in a while!"

Jopiteskygll says, "Guest89, that's funny; I'm going to get in trouble if my boss DOESN'T see this on my screen!"

Galileo_radio says, "Hi, Guests in the 150s.  Earlier we were talking about the number of bytes in the various computers on the spacecraft.  Since these were designed in the 1970s, the total was less than we're used to in our PCs and Macs now."

Guest152 says, "Hi, i`m Gonzalo Rico from the Galileo school that was chating in the morning. We have trobles with the telephone line and lose the chat. The children was very sad for this."

Marcia_nims says, "HI Gonzalo, glad that you're back."

Jopiteskygll says, "For those who have never looked at the Galileo web site (http://www.jpl.nasa.gov/galileo), we have a new image every work day.  Today, it's a near infrared map showing the distribution of sulfur dioxide frost on IoAs you might expect, there's not much frost in regions where there are volcanic hotspots (too hot).  Take a look!"


Galileo_radio says, "The radio equipment that I work with was also designed in the 1970s.  Our spacecraft transmitter puts out only about 15 watts.  That's only 3 times as much as a CB radio and far less than a radio or TV broadcast transmitter."

Marcia_nims says, "All guests, care to guess how many hotspots NIMS Io observations have detected to date?"

Leslie_outreach says, "Guest152, Where is the Galileo school? Do I remember you from our last chat?"


Guest152 says, "Thanks Marcia, but now i am by myself, because i`m out the school, with  another telephone line. By the way leslie, Galileo School is in Xalapa Mexico."

Marcia_nims says, "No guesses for the number of Io hot spots detected by NIMS?"

Ggerry-snyder says, "42?"

Stuart_s_uvs-euv says, "Marcia, can I play?  20?"

Galileo_radio says, "Guest152, can you tell us why your school was named for Galileo.  How long ago was it named?"

Jimericksonsso says, "47'476"

Jimericksonsso says, "retry 47"


Marcia_nims says, "Good try, Gerry, but too high...  so is Stuart's guess"

Marcia_nims says, "Hint:  The answer is in double digits however"

Dan_erickson_cds holds up all his fingers and toes and looks confused.


Galileo_radio says, "Welcome new guests!  What have you been hearing about the Galileo mission lately?  Or how did you come across this Webchat?"


Guest152 says, "ok galileo_radio. The school was named of course for the Great Galileo Galilei the porblem i have is that i`m just a father of the school who was help in this event. But i think the school have about 6 years."

Jopiteskygll says, "Someone asked about what the metallic hydrogen (hydrogen that has metallic pproperties) inside Jupiter looks like.  I've been asking around here, and no one is really sure; we're not even sure if it would be shiny or not!  But I'll see if I can turn up an answer."

Galileo_radio says, "Thanks for the answer, Guest152.  I hope your child is making a lot of new discoveries in the Galileo school, just as the great scientist did in his life?  What kind of science is your child interested in now?"

Lj says, "Is there any news about extended mission? Is it approved yet?"

Images_outreach says, "Marcia, Would you tell us something about how NIMS (the Near Infrared Mapping Spectrometer) and SSI (the Imaging camera) cooperate to create complimentary observations.  Why would you want to combine your data with images?  What do you learn?"

Guest152 says, "Well, in fact I have organized this sesion, because i`m an old reader of your pages in the www, and i see the opportunity for our children to be in contact whith this very interesting thing"



Jopiteskygll says, "Lj, there's no news yet about the extended mission; the big question is funding.  If it's approved, we'll see many more images of Europa, and possibly of Io as well."


Toddrocketenginr says, "Lj, the last I heard on GEM was positive for the outlook of funding for 2 years at roughly 15 million $/yr.  Plans are being made now to operate the spacecraft for a GEM mission."

Leslie_outreach says, "Randy_radsci, how much does radio science data tell us about the thickness of the ice crust on Europa, or other interior composition info?"



Galileo_radio says, "Hi, Randy.  Maybe you can tell our guests about some of the exciting radio science going on right now.  Why right now?  Because Jupiter is very close to the sun as seen from the earth.  The radio signal has a difficult time reaching past the sun to get to the earth.  There is another satellite up there, called SOHO.  It shows what the sun's corona looks like from earth orbit.  The SOHO corona images are on the Web."


Toddrocketenginr says, "Lj, of course, you know how the political winds can change direction!"

Lj says, "It would really be sad to see Galileo functional but doing nothing"

Images_outreach says, "On the way to Jupiter, Galileo flew by Earth a couple times.  One interesting result is that no signs of intelligent life were detected by the imaging camera.  What did the Near INfrared Mapping Spectrometer learn?"


Toddrocketenginr says, "Lj, I agree, but there is a precedent.  Does anyone remember which planetary spacecraft was recently "turned off" to save funds for more pressing projects?  I don't think Magellan counts, since the decision to aerobrake and eventually plummet to Venus was a good science trade."


Toddrocketenginr says, "Lj, also it would be sad to see Galileo scientists and engineers functional but doing nothing :-)"



Randy_radsci says, "Radio Science is presently collecting data for the Solar Wind Scintillation Experiment in collaboration with SOHO.  The purpose is to map the creation of the solar wind structure."

Randy_radsci says, "These experiments have been going on for about 5 years now which really helps in the time evolution over a solar cycle."

Galileo_radio says, "Randy_radsci, I think I heard on the radio news this morning that there was a big ejection of mass from the sun a few days ago.  It may have harmed a communications satellite in earth orbit.  Did this mass ejection show up in any of your radio science data?  I was told it showed up in the SOHO visible light images."



Randy_radsci says, "The upcoming closest approach at Europa will allow our Celestial Mechanics Team to peer inside the interior of Europa to determine some of the mass distribution and density of the satellite."



Lj says, "Was it one of the Pioneer spacecrafts?"


Toddrocketenginr says, "I have a question for the remote sensing types--how do we select an Io aimpoint?  It is such a diverse and interesting surface.  Or is all close imaging able to be done sufficiently near the moon to get the coverage of the different terrain types?"

Galileo_radio says, "Randy_radsci, do you think the Celestial Mechanics experiment (peering inside the interior of Europa) will tell us something about how big or deep the ocean underneath the ice might be?"



Randy_radsci says, "We have stopped tracking the spacecraft for just over a day.  But, during the course of this experiment, we have been able to corralate the coronagraphs with the radio data."


Toddrocketenginr says, "Yes, Lj, I think you are right that it was a Pioneer spacecraft."

Lj says, "Whic one was it?"

Toddrocketenginr says, "Hmm, Lj, I am not sure--Pioneer 10 or 11?  (the first visitors to Jupiter, incidentally!)"

Randy_radsci says, "hmmm...I'm not sure.  The gravity field pass could certainly tell us about the mass density of the planet.  that's something to ponder....."

Marcia_nims says, "Hi Images,  Basically, SSI provides a good deal of information about the surfaces of Jupiter's moons due to it's ability to take high resolution images.  NIMS is a spectrometer which can determine surface composition and distribution of different surface materials.  By merging the two instruments data together, we can make the data "go" further scientifically.  Combining the data allows us to see not only what the surface looks like in a particular area but also what it is composed of.  For the Callisto planning most of the observations are cooperative.  NIMS and SSI seek out the same real estate."


Lj says, "I guess it has to be Pioneer 10 because 11 was turned off a while ago. I could be wrong."

Galileo_radio says, "Toddrocketenginr, what I'd heard about Pioneer 10 and 11 is that one of them is still functional and is tracked occasionally.  The Pioneers have radioisotope power supplies because their paths are so far from the sun.  I think the nonfunctional Pioneer is that way because its power supply finally decreased below what its radio and instruments needed."

Dan_erickson_cds says, "The two Voyager spacecraft launched in 1977 are still being operated. They are expected to reach the ÒheliopauseÓ by 2004. This will be our first look outside the bubble created by the solar wind."


Marcia_nims says, "Hi Images,  NIMS detected methane in rice paddies during the Earth encounters.  Sorry for the delay in answering."

Toddrocketenginr says, "We have 15 minutes left in the session--any outstanding questions that we can try to answer before the end of the chat?"

Toddrocketenginr says, "I mean outstanding as in "not yet answered"--there's no pressure here, since there is no such thing as a bad question!"

Guest186 says, "regarding life on Europa, what organic compounds have you found ?"

Guest152 says, "pioneer 11 was turned off on september 1995"

Guest89 says, "What are the reasons for the Galileo instrument (was it the spectrometer) being stuck in the same position?  Was it radiation from Jupiter?  What are the consequences for the mission?"

Dan_erickson_cds says, "Guest89 must be referring to the Photo Polorimeter."

Guest89 says, "Dan...I think so...its the one that rotates with different filters."

Lj says, "I have one more question about UVS animation that was released some time ago. I only see the description."

Leslie_outreach says, "guys, This is interesting stuff for eachother, but I think we might be scaring some of the guests who are looking in with the techie talk!"

Marcia_nims says, "Hi Guest89, Actually it was the photopolarimeter.  The good news is that the filter wheel moved during the last attempt to move it.  It is no longer stuck.  The problem is still under investigation and the consequences are some lost observations.   Keep reading the Galileo home page for updates."

Ggerry-snyder says, "As I remember, the filter wheel came unstuck when the instrument was made cold by turning off heaters."

Leslie_outreach says, "randy_radsci, did Voyager give us the info about the inside of Europa that we now have, or was it from somewhere else, like earth-bound measurements?"

Guest89 says, "Marcia...Wasn't moving it a risky maneuver.  What if it got stuck in between sensors...we would have nothing...It was broke...but at least it was broke on a functioning sensor."

Guest89 says, "Hi Jim.  Do you know who I am?"

Stuart_s_uvs-euv says, "Hi Lj, what was your question about the UVS animation?  I believe it was a Jupiter aurora observation."

Leslie_outreach says, "Guest89, you can keep up with Galileo's happenings with our electronic mailing list:  see http://www.jpl.nasa.gov/galileo/mail.htmlh"

Lj says, "Yes, I am having troubles playing it. I only see the description, like there would be no animation?"

Randy_radsci says, "Leslie_outreach, i don't believe that either of the Voyagers had an encounter with Europa so any information we have now must have been thru remote sensing instruments (earth or spacecraft)."

Leslie_outreach says, "randy_radsci, would that also be radio data?"

Stuart_s_uvs-euv says, "I'll check with the outreach folks (who put such things on the web page) to see if it needs fixing.  Thanks."

Marcia_nims says, "Guest89, I'm not privy to all the information that went into making the decision to move the filter wheel, but I believe that the outcome of leaving the wheel in the stuck position would have meant no or minimal observations.  Sometimes it pays to be bold."

Toddrocketenginr says, "Someone had a question about organic molecules on Europa.  If I recall the press conf. correctly, Ron G. said that they are inferring organics on Europa as part of the of the "is their life there?" debate.  I read from this that no actual organic molcules have been detected yet.  Maybe no,t, though."

Randy_radsci says, "Leslie_outreach, no...in order to gain the information that we did at Ganymede, the spacecraft would have to be in fairly close proximity to the planet."

Randy_radsci says, "Leslie_outreach, did I answer your question?  I may have lost the thread."

Leslie_outreach says, "Toddrocketenginr, this is correct.  So far, ground based measurements of Europa showed as-yet unidentified contaniments in the ice.  I believe the presenc..."

Leslie_outreach says, "Toddrocketenginr, We think organics must be present on Europa since meteorites continually hit the surface, and organics HAVE been detected in meteorites and asteroids."

Matthew_ssi says, "Lj, I can see the animation page at http://www-pdsimage.jpl.nasa.gov/cgi-bin/GCBGenDownloadOpts.pl?11041996 without problem.  From there you can pick which version (MPEG or QuickTime) to download.  These are BIG files and you need a suitable player for your computer.  I believe there is a link for player information somewhere on the Galileo webpage at http://www.jpl.nasa.gov/galileo   ...hope this helps."


END OF MORNING SESSION

Guest215 says, "Does anyone know what are those ridges on Europa?"

Guest216 says, "what riges?"

Guest215 says, "never mind. I read that they are of  unknown origin."

Steveaacs2 says, ""No one knows. First to figure it out wins and Eskimo Pie..."

Frozen says, "We wanted to know if there is an estimate of how thick the ice on Europa is?"

Guest215 says, "well, maybe Gallileo and the NASA guys will tell"

Guest210 says, "Not until 7:00 est"

Steveaacs2 says, "There's not a clear answer to the ice thickness. It's probably no more than a few hundred KM"

Frozen says, "What evidence is there that there is an "ocean" under the ice on Europa?"

Guest219 says, "If there is an ocean do you think anything could be alive in it"

Guest215 says, "Are there any images of the rings of Jupiter?"

Steveaacs2 says, "No hard evidence of an ocean yet but it's clear that the surface of europa is very young and that some process has let big chunks slide aroundmuch like ice flows move on earth"

Guest216 says, "Is the ice on Europa H2O or some other strange formula?"

Guest216 says, "there probably is something alive in it."

Frozen says, "We saw an image of the rings on the Project Galileo site a few days ago."

Guest210 says, "Look on the Galileo website for ring picture."

Guest219 says, "How cold is it on Europa"

Frozen says, "The Galileo tour had a lot on Jupiter's magnetic field.  What exactly is the effect it has?"

Steveaacs2 says, "I don't know the europa surface temp off hand but the galileo web site"

Steveaacs2 says, "will have it. or ask again later when the sci folks come back."

Guest219 says, "I am a homeschooler and this is a major cool way to do science"

Steveaacs2 says, "Jupiter has a big complicated magnetic field which interacts with the moons in many ways."

Guest216 says, "If there was any evidence of life on Europa, then the government would never tell us, I hope that there is."

Guest219 says, "your right about that"

Guest215 says, "on gallileo home page it says that some -240F on Jupiter"

Steveaacs2 says, "It will be a long and complicated process to prove convincingly that there is life on europa"

Guest215 says, "Has anyone heard about alien mining  operations on the moons of Jupiter?"

Steveaacs2 says, "the recent press releases on  ancient mars life are an example of thow that s"

Guest215 says, "Just read it somewhere on the net"

Steveaacs2 says, "sort of thing works.  For what it's worth, I've worked for NASA for 4 years and I've never seen the slightest hint of coverup or scientific censorship."

Frozen says, "We were wondering if Galileo found any after effects from the S-L 9 comet impacts?"

Guest219 says, "Yes just have to think of one"

Steveaacs2 says, "I think essentially all the effects of the SL-9 impacts have faded by this point."

Guest219 says, "Did Galileo take any strange pictures"

Steveaacs2 says, "the europa life stuff is all guesswork at this point. The first task is to figure out if there is really liquid water under europa's surface. Thats pretty tricky to prove in it's own right..."

Guest219 says, "Is there any chance of going on the surface of Europa"

Steveaacs2 says, "Galileo has certainly taken some pictures that have surprised the scientists. That's a good thing. It means we're learning new stuff."

Guest219 says, "How long does it take the Galileo to send pictures back to Earth"
Guest216 says, "I am representing the Science club in our school, and we wanted to know if the lines on Europa are from glaciers and if the ice is H2O?"

Steveaacs2 says, "it's technically possible to land stuff on the surface"

Guest216 says, "Are you gonna land stuff on the surface?"

Guest219 says, "Is it to cold to have life on Europa"

Steveaacs2 says, "I'm on the phone talking about sun sensors for a moment. Be right back..."

Guest216 says, "Guest219qqwwxxendxfor us it is, but I don't know about any alien lifeforms, they are genetically different"

Guest219 says, "What is Jupiter mostly made of"

Guest252 says, "Did you see the picture of Io ...it was very nice for me..."

Hines says, "All of the pictures that have been returned are awesome, in my opinion."

Marcia_nims says, "Hines, I'm rather partial to the NIMS images myself"

Steveaacs says, "Marcia, what's the latest theory about that  spectral feature you folks have found?"

Hines says, "What I want to see is a free-roving vehicle on each of the major moons of both Jupiter and Saturn, esp. Titan"

Hines says, "Which spectra feature are you refering to, Steve?"

Robinhood says, "How thick do you think the ice on Europa is?"

Marcia_nims says, "Steve, it could be one of many hydrated minerals.  Still working on it.  Not much more to report."

Hines says, "Robinhood:  Are you thinking what I'm thinking?  Drill through the ice and get a sample of the liquid water beneath, and test it for microbs!"

Marcia_nims says, "Hines, the spectral feature that Steve is referring to is a discovery NIMS made during the first orbit.  It is at 4.25 microns and could be one or more of many different minerals."



Steveaacs says, "The NIMS makes spectra in the infrared. They've seen a very distinctive feature at a particular wavelength on several of the moons and they've been trying to figure out what it is...  (I can explain more simply if that's too techie)"

Hines says, "No, I'm an electrical engineer and quite familier with spectra (fourier transforms, etc.)"

Marcia_nims says, "Hines, The spectral feature is seen on Callisto and Ganymede.  Callisto has the stronger feature."

Hines says, "Marcia:  But it's not clear what compound is creating the absorption line?"

Steveaacs says, "there was a recent conference about the possibility of oceans on europa and they discussed the possibility of melting down through the ice and then driving a remote control submarine around under the ice..."


Hines says, "Nebula:  I used to be one of those.  Now I'm an old engineer!"

Hines says, "Steve: Extremely cool idea!  Cost about 10 billion + I would guess..."

Nebula says, "steve:that sounds like 20000 leagues U the sea"

Hines says, "Nebula:  I'll bet it exceeds 20,000 leagues!"

Marcia_nims says, "Hines, that's true.  Unfortunately, there is a  whole host of possibilities from our spectral library.  We're still trying to determine exactly which one of those possibilities is the right answer."

Steveaacs says, "yea, a pretty cool idea. Not cheap, but probabaly doable technically."

Robinhood says, "The sub would be to cool but it would answer many Q's but make more"

Hines says, "Nebula:  I don't know how thick the ice is, I just suspect it to be VERY thick."

Hines says, "Does the spacecraft have any way of determining the ice thickness?"

Nebula says, "they can measure density of jungle"

Hines says, "Nebula:  Probably not, because Europa is quite a bit colder than Antarctica"

Robinhood says, "How cold is it on Europa"

Hines says, "Robinhood:  Science always creates more mysteries than it solves.  That's why it never gets boring!"

Nebula says, "hines: are you a scientist at the mission control"

Guest252 says, "no it is impossibel to find out how thich the ice is.."

Robinhood says, "Could anything Live on Europa"

Hines says, "Nebula:  I WISH!!!  Nope, I'm an engineer working on product data standards (very boring...)"

Hines says, "Robinhood:  That depends on what kind of compounds and geologic activity is happening under the ice."

Steveaacs says, "the only way galileo has to determine the thickness of the ice is to look at the surface and try and understand the ice flows and other surface processes. One thing we can already tell is that the surface of Europa quite young"

Hines says, "Robinhood:  Until we know over 50% of all that is to be known, every answer will reveil 2 or more things we don't know about.  At least, that's my theory."

Hines says, "Steve:  There are techniques that apply multi-dimensional DSP techniques to acoustical array signals used on Earth to map the contents of the crust, specifically to look for Oil..."

Hines says, "A soft-landing probe could apply the same technique to determine where the liquid portion of Europa begins."

Steveaacs says, "yeah, computerized tomography methods. They could be used on europa to make direct measurements of ice depth. You probably need several sites though..."

Hines says, "yeah, I can see that.  You would want to see how the thickness varies from place to place anyway."

Hines says, "Which really argues for a rover similar to the one going to Mars."

Hines says, "This is probably a dead horse, but I'm curious:  Have you given up on the high-gain antenna, or do you still hit it with impulses from time to time to see if a micro-meteorite or something has unjammed it?"

Guest267 says, "nice picture from hubble (lagoon nebula) http://www.stsci.edu/pubinfo/gif/m8wide.gif"

Marcia_nims says, "Hines, We've stopped beating the dead horse and moved on.  At this point, it would be an incredible amount of work just to take advantage of such a miracle."

Steveaacs says, "We made our final attempt to free the HGA after our last main engine firing.  There are some very agressive (aka risky) things we could still try, butr"

Steveaacs says, "but we won't even consider them till after the primary mission is"

Guest267 says, "the pic is from 22 january 97 !"

Hines says, "That sounds like a sensable course..."

Steveaacs says, "done. Probably not even then..."

Guest267 says, "and e really great Lagoon Nebula detail-gif --qqwwxxendxhttp://www.stsci.edu/pubinfo/gif/m8detail.gif   GREAT !!!"

Robinhood says, "What does a JPL engineer do"

Marcia_nims says, "I'm a member of the NIMS science team."

Guest278 says, "Well, I have a question concerning something I read in the October 30th. chat's transcription (forgive my poor implementation of english language)"

Guest278 says, "I read this (on that chat):"

Guest278 says, "Todd Barber, Propulsion Engineer: . . . . Wed, Oct 30, 10:00AM PDT (-0700 GMT)"

Guest278 says, "Todd barber said something about plans on descending some submarine-thingie in Europe (in the future -How far in it?)..."

Guest278 says, "Are there serios plans about it?"

Guest278 says, "Yep, a sub in the under-ice Europa's ocean... Think about it!!!"

Steveaacs says, "I'm a memeber of the team that flys the galileo spacecraft. We make sure the spacecraft is working properly, fix it when it breaks and send commands to make it do the science that the Marcia, et al wants."


Hines says, "I think we need a permanent station in Geosync orbit around Jupiter first, for it to relay data to."

Marcia_nims says, "Chat, We really try to support all OutReach activities.  It's important to share with the public what we discover.  We all benefit from that."

Hines says, "Steve:  Fix it?  Are you referring to software problems?  It's a bit hard to take a wrench to it..."

Robinhood says, "How sophisticated will the sub be if you do it?"

Guest278 says, "Please, send my regards to Ms. Nancy Vandermey's cats"

Steveaacs says, "software is the only thing you can really "fix" on a spacecraft, but there are lots of things you can do, like swapping to redundant hardware that are part"

Steveaacs says, "hardware and software.."

Hines says, "Robinhood:  The sad truth about projects such as the "sub" is that technology is the easy part of the equation.  The politics is where the real work has to be done. :-("

Guest278 says, "Can you "discard" some Galileo hardware from here?"

Marcia_nims says, "Hines, I suspect many times over the Galileo mission, the engineers would have liked to take  a wrench to it.  On the science side, we wished that they could.  One of the great things about working on Galileo is the people.  They have to be some of the most creative folks around."

Robinhood says, "Oh so it is harder to get it down in the water then to build it"

Hines says, "Robinhood:  That's true too."

Hines says, "Marcia:  I can believe that!"

Robinhood says, "Believe what"

Guest278 says, "Steve Collins (of AACS) said (Oct. 30th.): "There's even a conference in a couple of weeks to talk about the Europa ocean and how to"

Guest278 says, "What about it?"

Hines says, "Steve:  plans in the works to send a "rover" of some sort to one of the moons?"

Robinhood says, "That would be cool if it had a camera"

Marcia_nims says, "Hines, there are a number of Discovery class (small missions) with Io and Europa as prime objectives.  As to the details, I don't know."

Hines says, "On a different topic, I would like to commend you guys on the quality of your web pages; you've really done a great job getting the exciting data that's coming back from Jupiter out to the public."

Robinhood says, "You certainly have done a good job on the Web Page"

Marcia_nims says, "Hines, Thanks for the kind words.  I'm sure our Outreach Group will be thrilled to hear this."

Hines says, "Say, you haven't discovered any black objects that are 1X3X9 out there have you? :-)"

Hines says, "Perfectly smooth and black..."

Marcia_nims says, "Hines, No..  but we'll be sure to get out of the way."

Hines says, "Marcia:  Smart move..."

Robinhood says, "What kind of black object"

Hines says, "Robinhood:  "It's full of stars!""

Steveaacs says, "sorry, got pulled away to the phone.  There are some people talking about how to land a device on europa that would melt it's way down through the ice and deploy a submarine. Kind of wild, eh?  Still a dream though..."

Marcia_nims says, "Hines, HAL would agree as well."

Hines says, "I'm sorry Marcia, I'm afraid I can't do that..."

Hines says, "Steve:  Dreams are what this is all about."

Marcia_nims says, "Steve, no one from this morning guessed the number of hot spots NIMS has discovered on Io.  Guess I'll open it again for the evening session."

Hines says, "Marcia:  It's not 42 is it..."

Future says, "Whats the latest news on the stuck filter wheel?"

Hines says, "Marcia:  I just looked at the NIMS image of Io; it looks like there are 5 hot spots (depending how your definition of "hot")"

Guest287 says, "In November it was supposed to be a conference on Europa's Ocean. Is there a transcription of it somewhere?"

Future says, "Does anybody know the status on the filter wheel that got stuck???"
Marcia_nims says, "Future, The filter wheel is now unstuck.  This is a somewhat new development."

Future says, "Marcia: WOW!!! Good news :-) congratulations to the Galileo team!!!"

Marcia_nims says, "Hines, I managed to kill my Ichat session so I missed some messages.  But 5 isn't the right answer, you're getting warmer."

Hines says, "Marcia:  Warmer?  HA!"

Marcia_nims says, "Hines, Warmer but not hot."

Marcia_nims says, "Future, The PPR team brought in sparkling cider and bagels to celebrate....  It was a really great day for them."

Guest287 says, "Are the Cassini team members feeding from Galileo's data for improving their mission or are they just starting from scratch?"

Hines says, "Marcia:  There are 5 areas of the NIMS image available from the website that are either yellow or red..."

Hines says, "Is Cassini the next probe going to Jupiter?"

Marcia_nims says, "Guest287, some of the members of Galileo also work on Cassini so I'm sure there is some exchange of information but how much I don't know."

Marcia_nims says, "Hines, Cassini is going to Saturn.  It can be referred to as a sister ship of Galileo.  Some of the science objectives are similar."

Future says, "Marcia: How did the unstuck the filter wheel and when did it happen?"

Marcia_nims says, "Hines, which NIMS images are you referring to?"

Messier says, "i have a question about one of the photo's of "io" shown on the web today.........."What is that strange looking thing off of the horizon."?"

Hines says, "Marcia:  I see!  Has Cassini been launched yet?  I don't get to keep up with planetary science the way I used to."

Messier says, "it looks as if it is lifted "VERY" high off the surface!"

Marcia_nims says, "Future, The instrument heaters were turned off and the filter wheel was commanded to move and it did.  I believe this occurred last week.  The days and weeks blend together rather quickly around here."

Hines says, "Marcia:  Image is 11131996_full.jpg"

Marcia_nims says, "Hines, No Cassini hasn't launched yet.  They have been testing hardware and software for a while.  I don't recall when their launch window opens."

Guest287 says, "256 days until launch of Cassini"

Marcia_nims says, "Hines, does it have a name in the caption? and thanks for the assistance Guest287."

Future says, "Cassini will be launched Oct 6... thats when the launch window opens"

Hines says, "Marcia:  No caption.  It was taken on Sept. 6 during the G2 encounter."

Messier says, "would you happen to know what that big shap is off the horizon of "io" in the photo shown on the web today?"

Lefty61 says, "What would be definite proof of a liquid water ocean on Europa?"

Messier says, "it's really big and looks to me to be somhow lifted off the surface somhowf"

Marcia_nims says, "Hines, Found the image.  Anything that isn't blue is a hot spot.  While you counted correctly for G2, you haven't seen the results of the C3 data.  We found more hot spots then."

Bashar says, "Hello again Marcia, speaking from the Czech Rep.,; I'd turn attention to Europa, what do you think is the possiblility for the life there, and wcould you please explain how can an 'ice' errupition look like? (too many questions, right ;))"

Future says, "When will you know if you can extend Galileos tour with 4 to 6 more orbits?"

Hines says, "Marcia:  OK; glad to know I'm not completely crazy!"

Marcia_nims says, "Hi Lefty61, NIMS will be searching for a spectral signature of hexagonal and cubic shaped ice crystals which are indicative of liquid water in the near past.  Stay tuned for updates after the next orbit of Europa."

Messier says, "Hassent anyone seen my question......or am i in some kind of "waiting order.....please tell me."

Marcia_nims says, "Messier, please ask again.  We probably missed it."

Future says, "When will you know if you can extend Galileos orbital tour with 4 to 6 more"

Future says, "orbits?"

Lefty61 says, "Thanks. Will you be doing any more imaging of the four small inner satellites?"

Hines says, "Marcia:  OK, I looked at the C3 SO2 frost pattern; it looks like about 20 hotspots now."

Messier says, "ok.....on the photo of "io" on the web today there is a large shape of somthing off of the horizon....."

Messier says, "it seems to be lifted off the surface somehow"

Hines says, "Messier:  I saw it to.  It looks like a VERY tall mountain rising very quickly from the surface."

Marcia_nims says, "Future, We won't know about the GEM part of the Galileo mission until the next budget go round."

Messier says, "photo # 1211997.jpg"

Messier says, "well i dont think its a mountain.......it seems much to big........or can it be?"

Marcia_nims says, "Hines, you're warmer.   The last count I knew about was 12.  7 new hotspots in C3.  Hot spots are active thermal emissions.  Glad you're enjoying our data.\"

Hines says, "Messier:  One truism about Io; it is a VIOLENT moon.  With the kinds of forces it's subjected to, I wouldn't be surprised."

Future says, "Have you found any hotspots (gaysers) on Europa?"

Hines says, "Messier:  If it turns out to be a mountain, I think it will be very significant.  It might be the tallest mountain in the known solar system!"

Marcia_nims says, "Hi Future, no geysers or hot spots have been detected on Europa."

Messier says, "any chance anyone saw the "GUITAR" shaped thing on "Io", it's in the same photo i was just talking to Hines about.........."

Chat says, "This just came up in an edit here... is it pretty certain the Europa has a volcanic center?  It is, right?"

Hertzprung says, "What about guesses on water's temperature in Europa under the ice core?"

Messier says, "wow good news.......so as far as "my household" is concerned......i discoverd the tallest mountain in the solor system...........but could it really be larger than Olympus Mons"?"

Bashar says, "And adding to Chat's question how can I imagine a icy volcano?"

Hertzprung says, "Olimpus could be high, but not impressive, I think. It could be something to do with angles, huh?"

Guest306 says, "Aurthor C Clark predicted life on Europa in his book 2063, the 3rd book in the 2001 series.  What are the possibilities that he was correct?"

Future says, "Marcia: Any evidence of a more active (warmer) period in The past of Europa?"

Hertzprung says, "2010, if I recall well..."

Messier says, "well the more i look at it it shure does not look like any mountain to me........"

Hines says, "Guest306:  Actually this was originally predicted in 2010."

Marcia_nims says, "Hi Chat,  There was some discussion of flows of ice on Europa's surface which may have originated from volcanic processes.  NIMS thermal data could provide further information but at this point, nothing has been confirmed."

Messier says, "its shape is not like any mountain ive ever seen........it looks more like a "SLAB" of somthing"

Hertzprung says, "What about the "cracks" on Europa's ice-core?"

Hines says, "Messier:  It's not black enough to be that..."

Tayfun says, "As far as I know on Jupiter5 Galileo passed pretty close to Europa,"

Marcia_nims says, "Tayfun, It was actually Europa 4 orbit."

Messier says, "Well if it turns out to be a mountain......it most certinly will be the largest so far.......and the oddest shaped mountain also"

Hertzprung says, "16 follows"

Future says, "Did Galileo record any data on Jupiter5?"

Lefty61 says, "It took a picture of Amalthea."

Hertzprung says, "My partner (Russell) just opened the pod bay doors and told me we should get back to work, so good bye, and see you in this chat transcription!!! ;-)"

Tayfun says, "Marcia: No I mean Jupiter5, it must be around 40000 km, did you take any pictures?"

Marcia_nims says, "Hi Future, No.  The 5th orbit  was solar conjunction.  We could not monitor the spacecraft or the instruments so we had a brief respite from data."

Jopiteskygll says, "Of course, Marcia is being slightly sarcastic when she talks about having a brief respite frodata.  You can never be too rich, too thin, or have too much data :-)"

Marcia_nims says, "Jo, do you know me to be sarcastic\"

Future says, "Marcia: ok... so not one single bit of data was recorded on the tape-recorder?!"

Rracer says, "I have a group of kids to ask question if anyone is ready to answer."

Rracer says, "How fast is Jupiters red spot moving?"

Messier says, "HUNDREDS OF MILES PER HOUR"

Rracer says, "How large is jupiters red spot.... miles accross?"

Messier says, "i think at least 3 to 5 earth's can fit in it........"

Marcia_nims says, "Future, data was recorded in the 4th orbit which we refer to as E4.  We have stopped playing that data back during the solar conjunction period.  J5 closest approach.  The data return begins again this weekend.  Hope this clears up confusion."

Messier says, "im not shure"

Future says, "Rracer: so big that the entire Earth could fit in it!!!"

Rracer says, "That's large :-0"

Guest304 says, "Has the Hubble found any storms on the other gas giants with the same kind of longevity as the great red spot?"

Tayfun says, "Why are there missing parts in Europa images?"

Rracer says, "What is the average tempature on Jupiter?"

Nancy_seq_sys says, "the white ovals are storms that have lasted hundreds of years"

Messier says, "will the "Galileo" sience people I.D. themselves?"

Nancy_seq_sys says, "i'm nancy, I work on the Sequence team - i'm an engineer"

Marcia_nims says, "Tayfun, Sometimes data gets lost due to station outages.  This probably is the explanation for the gaps you see."

Marcia_nims says, "Hi Messier, I'm a member of the Near Infrared Spectrometer Science Team."

Future says, "Did Galileo conduct any gravity measurments during J4?"

Guest304 says, "Why have the storms on Jupiter lasted so long, whereas they are very brief on Earth?"

Jopiteskygll says, "Rracer, it dedepends how far you're looking from the edge of the spot, but it whirls around at 110 meters/second, which is about 240 miles per hour.  It takes about 6 days to spin around completely (like a pinwheel)"

Messier says, "So do you guy's lose alot of sleep during these times of data inflow?"

Marcia_nims says, "Hi Messier,  What is sleep?"

Messier says, "lol"

Rracer says, "Which moon is the largest and how big is it..."

Jopiteskygll says, "Messier, the Great Red Spot actually varies in size; it can hold anywhere between 1 and 3 earths, depending."

Robinhood says, "How similar was the magnetosphere to the one around Earth"

Messier says, "well i knew it was big..........that tells me more than i knew thoe..........thanks"

Tayfun says, "Marcia: But the gaps look very similar. Is it possible to playback them again?"

Robinhood says, "Is Ganymede the largest moon"

Guest314 says, "how many moons has jupiter?"

Robinhood says, "12"

Col says, "Is it possible for primitive life forms to exist on Europa?  Is there Carbon on Europa?"

Marcia_nims says, "Rracer, Ganymede is the largest of Jupiter's moons."

Future says, "Did Galileo conduct any gravity measurments of Europa during J4?"

Jopiteskygll says, "Rracer, Ganymede is the largest moon; iat just under 3000 km in radius (that's about 1800 miles), it's the largest moon in the solar system"

Messier says, "Im still hung up on that strange looking shape off the horizon of "Io"........it's so strange looking.........i wish i knew what it was for shure........are you guy's "certin" that it's a mountain?"

Jopiteskygll says, "Guest314, Jupiter has 17 *known* moons.  There's the possibility that there could be some we haven't discovered yet, just as Voyager discovered moons during its flybys."

Pizarro says, "Are there any plans to send a probe to Uranus or Neptune?"

Marcia_nims says, "Future, yes, if the data was lost, it can still be returned.  It is still on the tape recorder."

Bashar says, "Nancy, can you tell how can I imagine an icy volcanos, similar to those found on Europa's surface?"

Robinhood says, "The article I read said it had 12 moons"

Messier says, "you guy's probly have more photos to look through..........does it show anymore info on any other photo's?"

Guest293 says, "How long will the satellite be operational?"

Bashar says, "Is the ice being errupted as the lava on earth or there's some different prcess involved?"

Guest304 says, "Is there any evidence of auroa in the Jovian atmosphere?"

Jopiteskygll says, "Guest304, the reason why the storms last so long on Jupiter is one of the questions that scientists are trying to answer.  Some things that probably make a difference are that Jupiter is bigger than the Earth, it spins faster (so higher wind speeds are easier to generate), it has no solid surface to break up the wind, and it generates a fair amount of internal heat.  But there's no one given answer, yet."

Rracer says, "Which is the smallest moon of Jupiter?"

Pizarro says, "Hi, I would like to know if besides Galileo and Cassini there are plans to send probes to other outer planets"

Future says, "pizarro: there are plans to sen 1 or 2 probes to Pluto! the Pluto express!"

Jopiteskygll says, "Rracer, the smallest moon of Jupiter is Leda, maybe 8 kilometrs in radius"

Messier says, "doesent Jupiter have some kind of core ......."Solid" that is?"

Future says, "Messier: they think it could be a core of metallic Hydrogen..."

Toddrocketenginr says, "Pizarro, I have heard some talk about a Neptune orbiter someday.  Pluto should be visited by a JPL spacecraft within the next 10-20 years; this mission is probably the most well-developed.  Also, there is recent talk of a Europa Ice Clipper that would dropa projectile on the surface and collect the explosive fragments in aerogel to return to the Earth!"

Messier says, "That could be some fun stuff to play with"

Future says, "Messier: Yes indeed! but you could never dive into Jupiter and pick some up"

Lj says, "Is there a homepage or other information on the net about Europa Ice Clipper"

Jopiteskygll says, "Rracer, wind sper can go up to 200 meters per second (, which is over 4000 mph!"

Messier says, "What will happen to "Galileo" after the mission is finnished.............will it travel out of our Solor system like Pionear?"

Pizarro says, "I think Galileo will orbit Jupiter forever...."

Future says, "Messier: Most likely Galileo will end up in a orbit around Jupiter until someday"

Nancy_seq_sys says, "if we do the GEM galileo may crash into Io someday"

Rracer says, "Was there any noticeable changes to the storms on jupiter after the Impact from the metiors"

Future says, "in the distant future it crashes into the atmosfhere!"

Toddrocketenginr says, "Messier, no such journey is in store for Galileo.  One of 3 things could happen: 1) we could eventually hit one of the Galilean satellies (most likely, 2) we could hit Jupiter (less likely), or 3) we could be ejected from Jovian orbit via a close encoutner w/ Jupiter.  This would occur many decades from now..."

Pizarro says, "It could also crash against a sat."

Messier says, "if so.........cant we recieve photo's and information indefinetly?"

Marcia_nims says, "Messier, yes, Galileo is nuclear powered."

Marcia_nims says, "Messier, you're right.  Indefinitely is not a possibility."

Jopiteskygll says, "Lj, tsay Messier, there are several possibilities about what happens to Galileo.  It might orbit Jupiter forever, it might enter Juptier"

Col says, "Does anyone know if there is Carbon on Europa?"

Future says, "Messier: Until the propellant is exhausted! then Galileo wont be able to point its antenna to earth!"

Marcia_nims says, "Hi Col,  Carbon has not been detected on Europa."

Messier says, "if it enters jupiter.......are there plans in order to be able to gather information during it's entry"

Col says, "How ling will it take for the propellant to run out?"

Marcia_nims says, "Hi Messier, If it enters Jupiter, there would be no way to collect the data."

Jopiteskygll says, "Col, it depends how much we do with the spacecraft.  If we maneuver a great deal, the propellant runs out faster."

Guest293 says, "How expensive was Gallileo to build?"

Jopiteskygll says, "Guest293, Galileo to date (from preproject planning to planned end of mission) will cost a total of $1.4 billion.  Since that's over 20 years, it works out to about 25 cents per person per year."

Marcia_nims says, "Hi Guest293, The Galileo mission has cost each person in the U.S. 25 cents per year for the length of 20 years.  Beat you JO."

Messier says, "I thought "nuclear power" would allow almost indefinet power........."

Messier says, "so that means it cost every person $5.00"

Jopiteskygll says, "say Messier, no, nuclear material has a half-life,during which it fissions into other elements or isotopes.  If the half life is very long, then the power lasts a long time."

Marcia_nims says, "Messier.  That's right.  $5.00.  Quite a bargain."

Stargazer204 says, "will the Casini mission be as successful as the Gallileo?"

Rracer says, "What is powered by the nuclear?"

Messier says, "oh........is the type of nuclear fule on Galileo different than that used on the Pionear spacecraft?"

Jopiteskygll says, "Stargazer204, that's a real set-up question--what are we SUPPOSED to say? :-)  Seriously, yes, we have every expectation that Cassini will do just as well (if not better) than Galileo."

Future says, "STARGACER: If sucsessfull? yes!!! .-)"

Messier says, "$5.00 is the best deal of the century"

Fred8615 says, "Does Cassini have a folded main antenna like Galileo?"

Marcia_nims says, "Hi Fred, No, Cassini has a solid main antenna"

Stargazer204 says, "I can't understand why the government wants to cut money from the space program"

Nancy_seq_sys says, "No, Cassini's antenna is fixed; they arent' launching on the Shuttle, which is why ours had to be deploya"

Col says, "Where will the Cassini mission go?"

Stargazer204 says, "Saturn"

Guest293 says, "Will it be possible to send a "manned" spacecraft to Jupiter someday?"

Future says, "Let´s mass produce planetary probes for less than 0.25 cents and send them out there!"

Europaphile says, "Whay not...the main problem is the radiation."

Messier says, "How do you guy's plan for "Incounters" with meteors flying through space that may hit Galileo?...........do you look ahead to see if any are in it's  path?"

Stargazer204 says, "I believe in Huge space programs instead of little and many"

Europaphile says, "it would be very nice to be ablre to do that after a series of unkmanned probes."

Future says, "Dont put all egs in one basket ;-)"

Stargazer204 says, "Space missions are a heck of a lot more successful than welfare and stupid services"

Europaphile says, "we need both"

Marcia_nims says, "Messier, Actually space is pretty vast, not like what's depicted in Star Wars asteroid or meteor shower (I forget which)."

Fred8615 says, "Don't let the Democrats hear you say that Stargazer204. :-)"

Stargazer204 says, "no, in my opinion welfare doesn't do anything but allow lazy people to sit on their rear-ends :=)"

Messier says, "Well it's pretty vast.........but the chance is still there.........are there any types of detecting instruments on bord?"

Col says, "Stargazer must have been born with a silver spoon in his mouth"

Europaphile says, "not true. lots of people on welfare are old, veryt young, or sick."

Stargazer204 says, "ya, but most are lazy"

Guest337 says, "Are we starting to see indications, or evidence that radiation is affecting some of Galileo's systems?"

Jnovak says, "This year, I understand the US is sending the cassini probe to Saturn.  Are the Europeans there right now with a probe?"

Jopiteskygll says, "sorry, we're experts here on science and space, not social policy."

Cynthia_imaging says, "messier, I don't think we can detect meteors, and even if we could, we couldn't get out of their way.  We just have to hope nothing"

Pizarro says, "wHY IS IT THAT THERE IS NOT A CLOSE ENCOUNTER WITH iO"

Future says, "Stargazer: There wont be any journeys to the stars before we solve our domestic problems!"

Col says, "Keep the topic on Galileo and keep your opinions on social matters to yourself"

Jim_gll_radio says, "Guest337, you asked if we're seeing effects of radiation on our spacecraft subsystems.  Yes, we had a problem with the on-board receiver two encounters ago.  We managed to get out of the problem, but it was a scare."

Stargazer204 says, "that is dumb, most of our domestic problems wouldn't be problems if people would do what the're supposed to do!"

Cynthia_imaging says, "pizarro, io is very close to Jupiter in a very high radiation environment, so the risk of going there is high.  We might go back there in if the mission is extended."

Jim_e_sso_mgr says, "jnovak - The cassini mission is actually carrying the Huygens probe built by the European Space Agency."

Toddrocketenginr says, "Messier:  actually, space is VERY empty, so we don't worry too much about hitting space rocks.  Even in the asteroid belt, we had to spend over 100 lbs. of propellant just to fly near an asteroid!"

Pizarro says, "Then there is a chance we shall get really close pictures from those volcanoes"

Stargazer204 says, "I am not questioning your knowledge, but how do we know who are the experts, and who are not?"

Messier says, "well........now that does shed light on how big space is.........to think we had to actually "try" and get close to an astroid......."

Cynthia_imaging says, "pizarro, yes that's what we're hoping for the end of the mission"

Future says, "Did Galileo make any gravity measurments of Europa?"

Tayfun says, "Is it possible to make Galileo pass through the outer layers of one of the plumes of Io if extended mission is funded?"

Europaphile says, "yes it did, but they are very preliminary"

Nancy_seq_sys says, "In GEM we will do a close Io encounter, assuming we get funded..."

Marcia_nims says, "Stargazer, that's a good question.  Might be a good idea for all Galileo people to identify themselves again."

Nancy_seq_sys says, "Tayfun, yes it is planned to attempt to go thru a plume at Io"

Jim_gll_radio says, "Future, randy_radsci can answer in more detail.  We are going to make radio gravity measurements on Europa at the next encounter; in fact, we're planning the details right now."

Messier says, "does anyone know if there has ever been a case were a space rock has hit one of our spacecraft?"

Fred8615 says, "How much funding is need for a GEM? (Just in case i should ever hit the Powerball lottery.) :-)"

Randy_radsci says, "Future, Galileo has not had the opportunity to make any significant gravity measurements of Europa.  However, in the next encounter, we will be coming within 590 km."

Jim_e_sso_mgr says, "messier - I know of at least one earth orbiter that has been hit."

Europaphile says, "that would do it"

Nancy_seq_sys says, "30 million, I believe"

Rracer says, "How many earths could fit in jupiter?"

Tayfun says, "Nancy_seq_sys: Which plume will it be? Is it dangerous?"

Nancy_seq_sys says, "tayfun: not sure which plume - depends on ewhich ones we see are active while doing the previous callisto encounters"

Buggs says, "I'd like to know: whats the height of the doble-ridges shown on  http://www.jpl.nasa.gov/galileo/europa/PIA00542_full.jpg and why are there so much of these double-ridges .. and whats the secret about ?? seems very strange to me"

Jnovak says, "What is the current theory of Europa's Ice/Water surface as analyzed by Galileo's most recent flyby."

Europaphile says, "still a possibility."

Jim_gll_radio says, "Rracer, that could be calculated a couple of different ways.  Do you want the "earths" to be squashed to fill all the available space inside a Jupiter sphere?  Or leave them round?   8-)"

Guest337 says, "Where on the spectrum does Galileo's Low Gain Antenna transmit?  How do you check for errors?"

Rracer says, "Leave them round"

Guest328 says, "Has there been much evidence of glacial events on the Europan surface?"

Jim_gll_radio says, "Guest337, the Galileo low-gain antenna transmits at S-band.  The approximate frequency is 2295 MHz.  (It would have been the same frequency with the high gain also.  But we would have in addition had an X-band with the high gain.)"

Messier says, "Are all of you scientest at the same location in the United States?.........im in las vegas"

Stargazer204 says, "I just wanted to say thanks to all of the experts here for taking the time to answer questions that we all want to know! :=)"

Closecall says, "Has Galileo seen "northern lights" in Jupiter's atmosphere?"

Messier says, "i second that Stargazer"

Future says, "Will E6 gravity measurment answer the question of liquid ocean?"

Europaphile says, "being an "expert" means we have a learners permit."

Marcia_nims says, "Europaphile, nicely said."

Cynthia_imaging says, "future, I think that the E6 gravity measurements will help, but we"

Jim_gll_radio says, "Good point, Europaphile, "expert = having learner's permit"!  I enjoy being paid to work and learn on the job, as I'm doing today."

Stargazer204 says, "how often does this chat session occur?"

Jim_e_sso_mgr says, "closecall - I recall seeing images of aurora in Jupiter's atmosphere."

Dan_erickson_cds says, "Closecall, I believe that the Ultraviolet Spectrometer (UVS) has measured the aurora which we would call the "northern lights"."

Leslie_outreach says, "Closecall, absolutely we see aurora in the polar regions of Jupiter"

Fred8615 says, "I thought Voyager had seen auroral lights?"

Rracer says, "Are there any theories to what the core of  callisto is mad of?"

Closecall says, "Jim, have any of those aurora photos been posted on the web site?"

Vjq says, "is there really water in europa"

Tayfun says, "Cynthia_imaging: How many pictures of Io were taken on C3?"

Dan_erickson_cds says, "Fred8615, I think you are right. Voyager did make some UV measurements of the aurora."

Cynthia_imaging says, "vjq, there definitely is water, but we're not sure if it's liquid or solid ice"

Guest354 says, "Hello Marcia, My first question is to all Galileo members: after more than one year since Galileo arrived at Jupiter, who"

Vjq says, "how about the new images, what do you know so far?"

Jim_e_sso_mgr says, "closecall - I don't think they have been posted, but I haven't looked lately.  Leslie, do you know?"

Leslie_outreach says, "Closecall, Galileo measures Jupiter's aurora primarily in the ultraviolet wavelengths, and not so much the visible, so no "photos" are available."

Jim_gll_radio says, "Guest354, I'm Jim Taylor.  I have been on the Galileo flight team since before launch in 1989, and have worked on the spacecraft radio, antenna, and data subsystems all this while.  Also I'm involved with the big (70-meter) tracking antennas here on earth, which receive Galileo's signal."

Messier says, "Cynthia:  Is it very difficult to identify all thoes little things in all of the photo's?.....i mean  how do you know that what your seeing is what you think it is?........."

Toddrocketenginr says, "Fred8615, 30 mil out to cover it.  And aren't you sweet! :-)"

Cynthia_imaging says, "8 total Io images were taken on C3, I think"

||data|| says, "What will happen to Galileo once you're done "using" it?"

Fred8615 says, "That I don't have yet of course."

Future says, "Does Galileo transmit back all data (images) from each encounter or does it get erased?"

Cynthia_imaging says, "messier, yes -- that's the big clallenge, to figure out how what we see in images relates to what's on teh surface"

Jim_gll_radio says, "Future, we do our best to transmit all the data back.  Some gaps are caused by problems with the tracking stations.  Whether we recover that data depends on how important the scientist says it was."

Messier says, "You have a very special "FUN" job Cynthia"

Buggs says, "will there be any color images from the E4 encounter ?"

Guest363 says, "How fast is the Galileo travelling?"

Cynthia_imaging says, "I love what I do!  :)"

||data|| says, "What have you learned (that's new) so far due to galileo?"

Fred8615 says, "Have there been any periodic attempts to try opening the main antenna or did you give up it long ago?"

Guest354 says, "My first question is to all Galileo members: after more than one year since Galileo arrived at Jupiter, who"

Messier says, "im glad you love your job.............it,s to all our benifit"

Robinhood says, "In the first picture of Europa what are the red wavy things"

Stuart_s_uvs-euv says, "Hi, I'm a science coordinator with the Ultraviolet Spectrometer Team (UVS and EUV, the E stands for Extreme UV), and I just joined the chat, although I was here this morning.  I saw some back-and-forth about Jupiter aurorae....  Yes, there have been plenty of aurora images posted, but I think they're mainly Hubble Space Telescope images from Earth orbit, done in close collaboration with the UVS/EUV Galileo aurora observations.    I believe that SSI (the Solid State Imaging camera, that takes most of the images that have been posted) has taken at least one visible-wavelength image of Jupiter that showed the aurora.  I don't know if it was posted on the web, though.  Any leads, Leslie?"

Randy_radsci says, "Guest354 your're getting cutoff after 'who'"

Leo_cheng says, "Xray: The SEQ team is the the team responsible for putting together the commands that control the spacecraft"

Jopiteskygll says, "Future, Galleo usually doesn't transmit say Robinhood, the red wavy things are cracks in the ice; the red color is false color."

Cynthia_imaging says, "robinhood, which first image?"

Jopiteskygll says, "Fred8615, we've tried everything to see if the main antenna has worked its way loose, and the answer is still, unfortunately, no.  Darn!"

Cynthia_imaging says, "vjq, Galileo probably won't be able to prove whether or not there's a liquid ocean, though if we saw erupting geysers that might help."

Jim_gll_radio says, "Fred8615, I'm sorry to say that we don't think there is any hope the high gain antenna "worked itself loose".  I think the last hope was when we fired the large (400 Newton) engine prior to arrival.  Didn't jar it loose.  I second that "DARN!""

Vjq says, "Europaphile, do you work with the galileo team?"

Guest354 says, "This is Nasser Randy: I'm sorry, I will repeat the question, My first question is to all Galileo members: after more than one year since Galileo arrived at Jupiter, how"

Stargazer204 says, "When Galileo's mission is over, what will happen to it?"

Xray says, "Leo, please could you explain me how can I imagine an icy volcanos, simililar to those found on Europa and how is the capacity of the memory onboard the Galielo?"

Jopiteskygll says, "Poipoi, the project science group, which is all the principal investigators on Galileo, fight it out for the targets.  The idea is to maximize total science, not to fight just for your own instrument.  Science is dividellit, magnetospheres, and atmospheres."

Dan_erickson_cds says, "data, An ion engine produces a very small thrust, but can do so continuously. We would still have needed a chemical engine to break into orbit around Jupiter. We might have been able to avoid all of those Venus and Earth flybys getting to Jupiter, Though."

Messier says, "It will stay in orbit about jupiter.........i just learned that"

Jim_gll_radio says, "Stargazer204, toward the end of Galileo Extended Mission, we'd want to fly the spacecraft close to the satellite Io.  The radiation is more intense down there.  Perhaps the subsystems wouldn't survive more than one or two of tehse encounters."

Europaphile says, "poipoi the imaging team selects the ttargets, with lots of good advice from key team members. Arizona State University is doing the main planning for Europa and Callisto, and Brown University for Ganymede. Alfred McEwen, now at the UA is doung Io."

Cynthia_imaging says, "xray, an ice volcano is just like a rock volcano, but with molten ice erupting (water!)"

Future says, "Jnovak:the data left on the recorder. But you all do a outstanding job :-)"

Marcia_nims says, "Hi Vjq, NIMS will search for hexagonal and cubic shaped ice crystals which are indicative of liquid water in the recent past."

Buggs says, "I'd like to know: what's the height of the double-ridges shown on http://www.jpl.nasa.gov/galileo/europa/PIA00542_full.jpg (Caption: Prominent Doublet Ridges on Europa) and why are there so much of these double-ridges .. and whats the secret about them ?? seems very strange to me !! please give an answer :)"

Vjq says, "how deep would that ocean be?"

Tekkno says, "is it nuclear powered?"

Guest354 says, "okay, my qustion to all members, how do you evaluate the perfomance of gallile so far and the science results attained by it and who do you compare it with discoveries at Jupiter by Voyager in 1979?"

Xray says, "And the memory, how big is it?"

Robinhood says, "will the Galileo run out of power and if so when"

Stargazer204 says, "This chat session is very educational and enjoyable, I hope our government realizes how important space missions are!"

Leo_cheng says, "Xray, I think you may be surprised to find that the RAM memory on Galileo is smaller than what you would find on a desk top computer today."

Messier says, "Who writes the softwear for the Galileo spacecraft?"

Messier says, "microsoft?"

Dan_erickson_cds says, "I do, among others."

Cynthia_imaging says, "buggs, I think the ridges are at most a few hundred meters high.  the doublet-ness is exciting because wedidn't expect them to be double"

Leslie_outreach says, "Closecall, there is one "movie" out that shows the UVS instrument looking at Jupiter's southern polar region and seeing emissions there.  It is low resolution.  Try http://www.jpl.nasa.gov/galileo/ganymede/110496.html"

Jopiteskygll says, "Messier, it's written in-house here.  We've got some incredibly talented and caffeine-addicted people who do that."

Leo_cheng says, "I think its much less than a Meg."

Poipoi says, "what compression algoithms were chosen after the antenna failure? (if that's not too technical: that's what I do!)"

Xray says, "Ok and my question then is way is it so? Isn't it better to have bigger memory onboard to store large amounts of date?"

Tekkno says, "is it nuclear powered?"

Jopiteskygll says, "poipoi, we use a variety of schemes, both lossy and lossless."

Robinhood says, "Will the Galileo ever run out of power and if so when?"

Randy_radsci says, "Nasser, if you have access to the GLL Web Page you can see several instances where Voyager data is presented along side GLL data.  The improvement is dramatic!"

Guest337 says, "How much bigger would Jupiter have to be before it "ignited" into a star?"

Jim_gll_radio says, "Guest354, I'll speak for the telecom subsystems.  They have held up very well.  We have a double set of receivers, exciters, power amplifiers, modulators, and command detector units.  We are still working off the first of each pair.  This is hardware inherited from the late 60s and early 1970s."

Cynthia_imaging says, "xray, remeber that Gailleo is based on over 20-year-old technology!"

Jopiteskygll says, "Guest337, it would have to be about 80-100 times bigger to be a star."

Future says, "TO THE GALILEO TEAM: CONGRATULATIONS TO THE SUCESSFULL RELEASE OF THE FILTER WHEEL!"

Xray says, "Really??? I thought that the newest technologies are used..."

Cynthia_imaging says, "messier, I think that the Galileo computer is about equivalent to a pocket calculator"

Jim_e_sso_mgr says, "tekkno - Galileo is powered by RTG's.  These use the heat of radioactive decay to create electricity."

Jopiteskygll says, "xray, we can't use the newwest technologies: we have to make sure that things are flight qualifiedspacecraft; it was launched in 1987, after all."

Robinhood says, "So will it ever run out"

Randy_radsci says, "Galileo will never return to the earth."

Marcia_nims says, "Messier, I wish I was."

Dan_erickson_cds says, "Galileo has software in two main engineering subsystems and in several science instruments. The engineering software is written at JPL with some help from Lockhead-Martin in Denver. The science instrument software is written by teams here and elsewhere in the US.Messier, with more powerful computers and more memory we could process the information better. We could not get many more bits to the ground, but each bit could encode more or better information."

Cynthia_imaging says, "leocheng, I'm amazed at what you sequencers do!"

Guest337 says, "What type of radiation is emitted by Jupiter.  How strong is it?  Is radiation is space also measured in rads?"

Guest335 says, "what are rads"

Messier says, "oh i did not realize that............thank you"

Leo_cheng says, "cynthia: I'm amazed at what you do!  It takes alot of people to develope a sequence."

Xray says, "Moreover if you can utilize only low gain anteana.."

Vjq says, "What are the posibilities of life under Europa's surface?"

Guest335 says, "There seems to be a lot of bugs in this still"

Messier says, "Well then after realizing that the computers on bord are so "old"......i say we must get more spacecraft up there a.s.a.p."

Marcia_nims says, "Buggs, The Navigation team does an incredible job."

Rracer says, "Take care and keep up the great work, I'm sure you are all under appreciated :-)"

Leslie_outreach says, "Vjq, we do think there is evidence for an ocean existing AT SOME TIME on Eruopa.  Like Cynthia_imaging says, we'll have more confidence that one exists right now if we spot a geyser, or evidence of a recent one."

Jim_e_sso_mgr says, "stargazer204 - one way a different processor adds weight is if it is not as radiation hard.  You then have to add lead shielding to protect it."

Dan_erickson_cds says, "Stargazer204, More computer power means more electrical power, more mass in the solar panels or RTGs."

Vjq says, "isn't europa affected by the same forces that cause io's volcanism?"

Buggs says, "so you have more time and more data for the E$ ?? or not ?"

Buggs says, "I mean E4"

Vjq says, "Are Io's conditions similar to those in earth billions of years ago?"

Marcia_nims says, "Buggs, Your assumption is correct."

Europaphile says, "buggs yes more E4 images will be coming donw."

Gerry-test says, "We now have much faster rad-hard CPUs--just did not back then."

Guest396 says, "What computer language do you use to program Galileo computers ?"

Guest335 says, "so          galileo has an antena.  Whats wrong with it and Why dose it have it .  for communicaton"

Future says, "Could you shield A Spacecraft with a electro magnetic field against the radiation?"

Buggs says, "E4 images are amazing :))"

Guest335 says, "hiow long will its power last"

Cynthia_imaging says, "yes, but jupiter's atmosphere is a completely different story from earth. :)"

Guest396 says, "You are very courageous using asembly language :-)))"

Gerry-test says, "Future--magnets have poles and poles let in radiation (in addition to messing up magnetometers)."

Guest335 says, "What s wrong wihht that  how does it effect it"

Jopiteskygll says, "Stargazer204, we haven't scheduled the next chat session.  Keep an eye on the Galileo home page (http://www.jpl.nasa.gov/galileo) for details."

Vjq says, "maybe this is a stupid question, but why the probe didnt take any images of jupiter's atmosphere?"

Dan_erickson_cds says, "Guest396, we have little choice. What higher order languages do you know of for an RCA 1802?"

Future says, "Garry-test: Darn :-) well... nice trye!"

Gerry-test says, "What higher order languages do you know of for an RCA 1802?"  FORTH"

Xray says, "Does Galielo uses superconductive materials or uses superconductive properties in some other way?"

Leslie_outreach says, "Stargazer204,  we have an electronic mailing list you can join, or you can watch our web page for an announcement"

Dan_erickson_cds says, "That is right, Gerry-test, there was even a C compiler for the 1802. Neither met our requirements for support, reliability, and real-time performance, unfortunately."

Cynthia_imaging says, "messier, that was one of the original plans for galileo, to have a camera taking sequences of images of jupiter's atmosphere and send back movies.  unfortunately with tbroken antenna, we can't send back whole movies...ujust single still images."

Stargazer204 says, "how do I join an electronic mailing list??"

Jopiteskygll says, "Vjq, you can send questions (which are answered on a time-available basis) to askgalileo@jpl.nasa.gov.  Otherwise, we're all pretty busy running the spacecraft..."

Guest337 says, "When was Galileo exposed it more radiation:  Now, in orbit around Jupiter, or during gravity assist when it was closer to the sun?"

Dan_erickson_cds says, "Vjq, most of us would be happy to give you an email address if you ask."

Marcia_nims says, "Xray, Callisto has already revealed some interesting things.   The surface isn't as cratered as expected.  There are definite albedo differences and surface composition differences.  It's an interesting place."

Guest335 says, "how will radiation effect Galileo"

Marcia_nims says, "Hi Guest412, No Ice volcanoes have been detected on Europa yet."

Xray says, "And do you have a clue for the albedo to differ so much on Callisto?"

Chat says, "How many people are a part of the Galileo team at JPL?"

Guest335 says, "So Radiation disturbs the communication with Galileo.  What can you do about it"

Future says, "Is the rem to high for humans on Ganymede or Callisto?"

Randy_radsci says, "Guest335, the instruments on board the spacecraft can be affected by radiation.  it could damage them greatly."

Dan_erickson_cds says, "Guest335, We code the data with redundant bits so that we can reconstruct waht was s3ent."

Guest335 says, "Like how , curosion , destruction"

Vjq says, "Is there any posible way in which termonuclear reactions can be sparked inside Jupiter's core, any space disaster?"

Jim_e_sso_mgr says, "chat - do you mean now - online - or presently working on Galileo?"

Tayfun says, "Cynthia_imaging: Were you able to receive all of the Europa images from C3? We have seen only one of them."

Guest412 says, "So, Europa may actually be geologically dead, like Mars?"

Marcia_nims says, "Hi Xray,  Check out the Galileo homepage for the NIMS image of Asgard in the C3 area.  There are compositional variations which tie in nicely to the albedo differences in the SSI images."

Messier says, "did you get that Stargazer?"

Cynthia_imaging says, "tayfun, there was only one c3 europa image."

Buggs says, "another question about Europa: on the picture  http://www.jpl.nasa.gov/galileo/europa/PIA00540_full.jpg   (caption Flows on Europa) I see some dark spots. could they result from impact ? they banged through the 'thin' ice and then it freezed up. is this possible ? so you will not have an impact crater .. just a smooth surface !""

Rob_galileo_ssi says, "Guest412: No, no active "ice" volcanoes have been caught in the act.  We are not sure if the surface of Europa is currently active.  If it is, finding current activity would be a low-odds proposition.  At the moment we are using the camera to fill Voyager gaps in coverage as well as sample the various terrains at high resolution.  Perhaps if an extended mission is approved we will be able to spend more resources on plume searches."

Randy_radsci says, "Guest335, in ways similar to how the electronics of your computer could be damaged by static electricity.  the instruments would simply no longer work."

Future says, "Can humans survive the radiation on the outer moons of Jupiter?"

Jim_e_sso_mgr says, "chat - I get to work with some of the best people on some of the best subjects you can think of."

Guest335 says, "Is it orbiting"

Stuart_s_uvs-euv says, "Chat: Where is the Dava Sobel quote from?  I 'd be interested in seeing what she wrote about planetary scientists...."

Jim_gll_radio says, "Future, I don't think the outer moons of Jupiter produce radiation.  Thus, a human who was shielded from the other environmental effects probably could find a place on any of these moons out of the charged particles zining by."

Dan_erickson_cds says, "Guest335, Galileo is orbiting Jupiter."

Stargazer204 says, "I have a question, why does it take a while to release the images from galileo?"

Guest412 says, "Are there any follow-up probes planned for Jupiter after the Galileo mission ends?"

Guest335 says, "I Dont know if i do or not.  Why?"

Jim_e_sso_mgr says, "stargazer - to make a long story short, we have to squeeze the images (and all the other data) down a 120 bps pipe.  It takes a while."

Chat says, "Stuart: Dava's one of Discovery Online's writers (she does our astronomy column... plug, plug), but this is from the New Yorker, Dec. 9, 1996:"

Stargazer204 says, "i'm not lieing, i just heard that Jupiter has 16 moons"

Gerry-test says, "Messier, no such rules. The scientists just need a little time to think."

Guest335 says, "There are not 16 moon s are there?"

Dan_erickson_cds says, "Guest335, if you have a web browser, I recommend visiting the Galileo home page at http://www.jpl.nasa.gov/galileo"

Jim_gll_radio says, "Future, let's get that outpost built on Mars first.  Then we can think about Jupiter's moons.   8-)"

Chat says, "..."Virtually every planetary scientist I've ever interviewed expressed the same sence of awestruck privilege, as though he were pursuing faforite hoppies on company time.""

Buggs says, "Rob_galileo_ssi: but this could be the evidence for a beneath ocean ... ?"

Stargazer204 says, "no, I don't think that we should make space probes cheaper and less capable, I think we should make them worth while"

Cynthia_imaging says, "stargazer, I think that we're concerned about extraterrestrial life because of the implications it would have for us -whether we're alone or not."

Stuart_s_uvs-euv says, "Bye Jim....  I will try to keep an eye out still, while I clear my desk of a few other things...."

Messier says, "Cynthia: how about you.....could you "PHONE HOME" if you disscoverd "life" on one of the moons?..........i mean real signs of life......like lights in some kind of order or somthing.......are there any rules in place to "intersept" thoes photos?"

Jim_gll_radio says, "Future, your idea of mass producing planetary probes.  I hope to be in on that.  At JPL, we use the term "darkened skies", referring to the number of spacecraft we hope to have the Deep Space Stations tracking.  I hope we figure out how to do these many small probes."

Rob_galileo_ssi says, "Buggs:  Ice can deform plastically, too, so a relatively smooth scar from a meteorite strike does not imply water just beneath a brittle icy surface layer.  Another concern is when such an impact/healing might have occurred; most folks are interested in whether there is an ocean under Europa's surface right now, when the macula might by many millions of years old.  Lots of uncertainty.  Maculae might also represent volcanic centers, too.  We're still trying to sort it all out."

Stargazer204 says, "but that is not important in the longrun"

Cynthia_imaging says, "messier, I'm not aware of any such rules.  If we found real signs of life in any of the pictures, I don't"

Gerry-test says, "The existence of other life could give clues about how life started here."

Europaphile says, "The search for life gives us perspective on ourselves."

Cynthia_imaging says, "I think that's one of the reasons taht we (scientists) are so skeptical about reabout the "

Guest432 says, "Rob:if there is a sea under the ice in Europa, and a meteor did impact and bbreak through the surface, would tidal forces influence the way the crater formed looks like?"

Future says, "YES!! maybe the ORIGINS program will give us an answer before 2020!"

Marcia_nims says, "Europaphile... It has definite possibilities."

Cynthia_imaging says, "future, you mean saturn's satellite titan, the one with the atmosphere?  I don't think the atmospheric pressure there is high enough for a person with just an oxygen mask, and I think it' spretty cold besides."

Gerry-test says, "Just would like to correct one error on the Galileo web page. Venus and Earth will be advanced in their orbits around the Sun because of the Galileo flybys, not retarded. Galileo gained energy, and the planets lost energy. Therefore their periods decreased."

Stuart_s_uvs-euv says, "About Titan, my recollection is that it's quite cold at the surface, although the pressure is about the same as Earth's (not oxygen, though)."

Marcia_nims says, "Stuart so in this case you'd only freeze?"

Cynthia_imaging says, "it's true that titan is definitely an interesting place -- the cassini mission to saturn willl have a probe for titan's atmosphere, as well as doing radar mapping of the surface."

Jim_gll_radio says, "Sorry, future, I'm no rocket scientist, only a communications engineer.  I think I've heard the thrusters are bi-propellant; I know they talk about fueland oxidizer."

Fms says, "Since the main antenna has not opened on Galileo you are using the smaler one... do you use any special signal coding to ensure the communication (reed solomon error correction) or do you simply use a repeat block on error scheme?"

Stuart_s_uvs-euv says, "Future: Sounds reasonable to me....  To Fjb: I believe Rob is right that it's mostly N2 (nitrogen), but there are also hydrocarbons like methane and ethane.  They've considered the possibility of ethane oceans on Titan, if I'm not mistaken."

Future says, "So if i understand it correct, a NASA astronaut would easily survive on the surface?"

Guest432 says, "will there be another chat like this anytime soon?"

Cynthia_imaging says, "E4 io lower resolution data in a few weeks."

Dan_erickson_cds says, "Thats right Fms, we are using both lossy and lossless compression."

Fjb says, "I think Europa would be better for a colony Future. Plently of fresh water after all. ;-)"

Marcia_nims says, "Guest 432.  Keep checking the Galileo webpage.  These chats are becoming fairly frequent and are always announced there."

Jim_gll_radio says, "Right, Fms, Galileo does have a "sophisticated data compression scheme"; I'm not sure that it's limited only to the imaging data.  I'm sorry I don't know more about it, especially since my supervisor designed a portion of it."

Dan_erickson_cds says, "The lossless compression achieves 3.5 to one on some instrument data."

Dan_erickson_cds says, "The lossy scheme is called Integer Cosine Transform. It is adjustable. More compression...less quality. We get from 10 to 1 up to 90 to one out of that scheme."

Fms says, "Dan_erickson_cds: oki, a DCT variant..."

Rob_galileo_ssi says, "Fms: Imaging data can be compressed in a couple of ways: (1) lossless, using a Huffman scheme; and (2) lossy, using what is called ICT for integer cosine transform - really an integer version of the DCT process that I believe is at the heart of JPEG schemes.  I don't know all the details.  An integer scheme is a better match to Galileo's on-board computing capabilities."

Messier says, "anyone:what is the core of jup. made of ?"

Gerry-test says, "The ICT compression is the same basic scheme as used in JPEG files."

Dan_erickson_cds says, "Right. We didn't have enough processing power to use floating point, so we devised an integer algorithm."

Jim_gll_radio says, "If any of you have questions about the communications or the ground antenna system, give me an e-mail shout at jtaylor@galileo.jpl.nasa.gov"

Buggs says, "will tere be infrred-imaging with NIMS and Europa ?"

Guest445 says, "Was the radiation impact on the Galileo greater in its orbit around Jupiter or in its gravity assist around Venus?"

Cynthia_imaging says, "jupiter's atmosphere is mostly hydrogen and helium"

Buggs says, "Jim do you have an 24 hours contact with galileo ?"

Gerry-test says, "Future--your last comments almost sem familiar.   ;-)"

Marcia_nims says, "Hi Buggs, yes NIMS has been observing Europa.  In fact one of our images appeared in Scientific America this week.  We have returned some of the E4 Europa data.  Everyone is working feverishly to get it released to the public soon."

Dan_erickson_cds says, "Much greater radiation impact around Jupiter. When we went in close for the IO flyby and Jupiter Orbit Insertion, we used up nearly half of our radiation budget. We hope that the budget was conservative."

Jim_gll_radio says, "Buggs, most of the time, we do track Galileo 24 hours a day.  We've been out of touch with the spacecraft for about 10 days because the radio path is currently too close to the sun.  Hope to get that data back starting this weekend."

Buggs says, "that great Marcia :-)="

Fjb says, "What do you mean by radiation budget?"

Cynthia_imaging says, "I think radiation budget is the total lifetime amount of radiation the spacecraft can put up with before you start getting severe degradation of instruments."

Jim_gll_radio says, "Fjb, radiation budget refers to the amount of radiation apportioned for the arrival plus each of the encounters, which adds up to the total the subsystems can survive."

Future says, "Will you take a full color global picture of Jupiter some time during the mission?"

Dan_erickson_cds says, "The mission was designed to not exceed this total radiation dose during the prime mission."

Buggs says, "yes thats what I meant :)"

Cynthia_imaging says, "guest457, one of the reasons people are currently so excitedabout europa is that there's the possibility of a liquid ocean under the ice in the past, and maybe even today.  I fyou have liquid water, heat, and organic material, you could get life.  So it's possible....."

Rob_galileo_ssi says, "Guest457: Our view of life is perhaps biased toward requiring liquid water.  Europa is the best candidate for having liquid water currently, but so far all evidence is inconclusive.  If liquid water is present on Europa, it is probably beneath the icy crust and out of direct sight."

Cynthia_imaging says, "I'm not sure if any global jupiter images are planned -- so far, I've seen lots of cluseups."

Messier says, "I would just like to thank all of you for your time this evening............one final question.........."IS IT FARTHER TO THE MOON OR BY BUS?"

Guest483 says, "how can you orient to the earth?"

Cynthia_imaging says, "how can you orient what to the earth?"

Guest483 says, "who planed the mission Galileo?"

Dan_erickson_cds says, "Guest483, planning these missions is a team effort with many reviews."

Dan_erickson_cds says, "Planning involved JPL, NASA, the science community from around the world, and some industry participants."

Jim_gll_radio says, "Sorry for the rude departure.  I got knocked off the network, all this high technology.  8-)"

Guest483 says, "ok but how start this effort. Is the idea of one person or a team?"

Marcia_nims says, "Hi Guest488.  Don't shake your head.  Ask us a question instead."

Dan_erickson_cds says, "That's a good question, Guest483 says, I don't know for sure."

Hines says, "Dan:  I work on DARPA programs; I can relate to "reviews" 

Fjb says, "Remember the 7 new moons around Uranus discovered by Voyager?"

Fjb says, "Happened right about the same time the Challenger sguttle blew up."

Marcia_nims says, "Future, The naming of any newly discovered body has to go thru committee.  Ouch!!"

Fjb says, "There was recommendation to name the moons after the astronauts..."

Hines says, "Marica:  Then they should all be named m1, m2, m3, etc... :-)"

Future says, "or some new moon orbiting Saturn"

Jim_gll_radio says, "I for one like Future's idea for naming a moon for Sagan.  People have suggested naming something at JPL for him.  He was greatly involved with some of our planetary spacecraft programs, including Viking and Galileo."

Fjb says, "But the IAU, in it's infinite wisdom, chose to following the custom of naming them after Shakespearian characters."

Dan_erickson_cds says, "Why don't we name the asteroids "Sagan" there are billions and billions of them."

Marcia_nims says, "Hines, I'm surviving on one oatmeal raisin cookie and an espresso...."

Dan_erickson_cds says, "You have expresso?"

Dan_erickson_cds sighs deeply.

Fjb says, "There is a Sagan asteroid I think. I know there's one for Clyde Tombaugh, who just passed away too."

Jim_gll_radio says, "Dan, one special one out of those "billions and billions" would do the trick.  8-)"

Marcia_nims says, "Dan, from Starbucks at 7:30 this morning"

Guest483 says, "Why  I have the fealing that the pics of Voyager have more resolution than Galileo. Is that right? I mean that Voyager send more resolution pics in one pass than Galileo made in 4 (at the time)"

Future says, "the moon around Ida, has it been namned?"

Marcia_nims says, "Guest483, The images taken by Galileo are sometimes 100times better resolution that Voyager.  But you are right about the volume of images."

Jim_gll_radio says, "I think Ida's moon *was* named, Future.  Wasn't there a contest, or at least a call for suggestions, with some official body making the final decision?"

Fjb says, "Dactal"

Hines says, "Guest483:  The volume if images can't be helped because of the stuck antenna, I believe"

Fjb says, "Dactyl"

Fjb says, "Something like that."

Marcia_nims says, "Future, the moon of Ida is named Dactyl... since I helped discover it, I got to help choose the name from the many suggestions from the contest."

Jim_gll_radio says, "Marcia, help an old radio engineer remember.  What's the origin of the name Dactyl?"

Guest483 says, "I don't talk about distance, Galileo have made  more close ups I have no doubt, But i talk about resolution in the pics. Clarity."

Fjb says, "Future, if they name anything after sagan, it ought to be a feature on Mars. It was after all, his favorite."

Future says, "Fjb: yor absolutely right about that! :-)"

Hines says, "I think a star should be named after him."

Marcia_nims says, "Hines, Dactyl showed up in the SSI and NIMS data and the choice of name was a joint decision.  The name was then suggested to the IAU and they accepted it.  Dactyl was the name of the people who hid Ida from harm.  Ida was a wet nurse of Zeus, if I recall."

Future says, "We got billions and billions of them take a pick :-)"

Hines says, "Marcia:  So it's not the back half of a Teradactyl then? ;-)"

Future says, "Why not an entire Galaxy? the Sagan Galaxy!"

Hines says, "Future, pick one with a class M planet in it, please!"

Fjb says, "You do know Johhny carson said that WAY more than Sagan did. In fact, I don't think he ever actually said it himself. :-)"

Marcia_nims says, "Hines, no but it sure was better than referring to it as Elvis's cadillac or Mars Observer.  We have sick sense of humors."

Hines says, "No, what Carl said was "Billions of stars in billions of galaxies".  I used to tape Cosmos off of PBS"

Future says, "Fjb: i concur! he said billion but not b & b of stars ;-)"

Hines says, "Marcia: so do I."

Fjb says, "I'm so ashamed. I only have one Cosmos tape. :-("

Hines says, "I honestly don't recall Johny Carson talking about billions of anything, but I didn't watch him that often."

Jim_gll_radio says, "I couldn't let this teradactyl thing go, Hines.  My Random House says dactyl is literally the Greek word for "finger".  I can't find TERAdactyl, though."

Guest483 says, "Marcia how could you know that Dactyl is in orbit around Ida?"

Hines says, "Jim:  I can't spell for beans so it might be some other spelling.  I do know that what I was trying to spell is a flying dinosaur though."

Fjb says, "Starts with a P"

Fjb says, "Silent, but a P."

Marcia_nims says, "Guest483, we were able to spot the satellite in numerous observations taken over a five hour period.  That gave enough data points for navigation to do sample orbits."

Hines says, "Jim:  Or possibly 10?12 Dactyl's possibly :-)"

Future says, "Sagan has in a sense become imortal, his message is beyond our system,"



Future says, "and on its way to M13..."

Hines says, "Actually, Sagan would be a good name for a space station."

Fjb says, "I made the suggestion about naming a new remote control observatory here in Louisiana I'm webmaster of after him..."

Dan_erickson_cds says, "Actually, the Voyager spacecraft are not yet to the heliopause."


Fjb says, "But the organization where it's located at doen't name buildings after people. :-("

Hines says, "Dan:  I believe Pioneer I recently passed the heliopause, didn't it?"

Guest483 says, "Wich of the volcanos of Io are now in activity? Loky Patera is one?"

Dan_erickson_cds says, "Maybee you can name it The Space astronomy, geophysical and astrophisical network."

Future says, "FJB: Astronomer! we have an observatory at our club, STAR it´s called here in Sweden."

Dan_erickson_cds says, "I don't think so. The voyagers are travelling faster than the Pioneers."

Fjb says, "Pioneer left earlier though."

Hines says, "Yes, but the pioneers went out much earlier"

Fjb says, "I can remember hearing about Pioneer 10 "officially" leaving the Solar System awhile back."

Hines says, "Last thing I saw indicated the pioneers were WAY the hell out there."

Future says, "aND SO DID Mars surveyuor!"

Dan_erickson_cds says, "I believe the Voyagers have now passed them. Let's see. How can we find out. There must be a web page somewhere."

Future says, "but path finder will arrive earlier .-)"

Future says, "Celestical mechanichs :-) its a mystery..."


Hines says, "Some day people will collect these probes and put them in a museum somewhere."

Fjb says, "Except for one of the Pioneers. We know that one will be blown up by Klingons in the 23rd century. :-)"

Future says, "Fjb: i thought it was V´ger :-)"

Dan_erickson_cds says, "Pioneer 10: Distance from Sun (1 January 1997): 66.48 AU"

Guest483 says, "Who are the people who drive the Pioneer? They are not in the JPL?"

Dan_erickson_cds says, "Ames Research Center in Mountain View Calif. run the poineer missions. They also designed Galileo's Probe."

Guest483 says, "How many of the Volcanos of Io are in actibity nOw? and wath is the distance the ejecta go over the surface of Io? (Sorry for my english)"

Dan_erickson_cds says, "Hines, Pioneer 10 is still farther from the Sun than Voyager I, but it is close: 66.48 AU to 65.3AU."

Hines says, "Dan:  Wow, I had no idea they were so near each other.  How long until V passes P?  2 - 5 years?"

Marcia_nims says, "Guest483,  NIMS has discovered 12 active volcanoes.  7 were revealed in the third orbit.  I can't give you an educated answer about the ejecta distance."

Hines says, "Marcia:  Will you be investigating that feature on Io that looks like an absurdly high mountain?"

Marcia_nims says, "Guest483, Let me rephrase... 12 HOT SPOTs..."

Future says, "Hines: known from now on as the "Sagan" mountain..."

Dan_erickson_cds says, "Hines, I'm too tired to figure that out now. I'm getting data from pages linked to by http://seds.lpl.arizona.edu/nineplanets/nineplanets/jupiter.html"