Douglas Isbell Headquarters, Washington, DC March 21, 1996 (Phone: 202/358-1547) David Morse Ames Research Center, Mountain View, CA (Phone: 415/604-4724) James Wilson Jet Propulsion Laboratory, Pasadena, CA (Phone: 818/354-5011) RELEASE: 96-57
Hubble has an especially rare and challenging task. Astronomers say it is unlikely such a comet will ever come this close to Earth again during Hubble's planned operational lifetime. Since Hubble is not actively controlled from the ground and the comet's position is not precisely known, viewing the speeding visitor will be especially tricky. The telescope will be preprogrammed to point at a selected spot in the sky where the comet will be at a specific time.
Planned Hubble science observations of Comet Hyakutake include high-resolution imagery and ultraviolet spectroscopy. Near the time of the comet's closest approach, Hubble should be able to see details as small as four miles across. Astronomers also hope to see jets of dust emerging from the comet's nucleus.
NASA's recently launched Near Earth Asteroid Rendezvous (NEAR) spacecraft is scheduled to take images of the comet as a calibration exercise. Although NEAR offers a different vantage point from Hubble, its camera was not designed to image objects at such large distances.
Several NASA-supported ground-based observatories also will be studying the comet during late March and in April as the comet approaches perihelion (its closest distance from the Sun.)
NASA's Infrared Telescope Facility (IRTF) on Mauna Kea, HI, will dedicate several days of observing time to study the release of dust and ice grains from the nucleus of the comet. These ices are composed primarily of water. Spectral observations of the molecules vaporized from the nucleus should provide samples of molecular abundances that were present at the time of the formation of the Solar System. The Extreme Ultraviolet Explorer spacecraft will make observations of neon and helium for comparison with the water production rates to be measured by the IRTF.
Images from IRTF and many other sources will be posted to a "virtual star party" on the Internet called the "Night of the Comet," sponsored by NASA's Ames Research Center, Mountain View, CA, NASA's Stratospheric Observatory For Infrared Astronomy (SOFIA) program, and its K-12 Internet Initiative. This home page allows anyone with access to a computer and a modem to post and observe Hyakutake images, track the progress of the comet, converse with NASA experts, learn about astronomy and participate in experiments.
"Although the project is just getting started, the initial response has been tremendous," said SOFIA project educator Bob Hillenbrand. "Virtually every state is covered, plus Puerto Rico, and observers are participating from every part of the globe, including Taiwan, Australia, Africa, Russia, South America and Europe."
"Night of the Comet" can be accessed via the Internet at URL:
Students in California, Virginia, New York, Delaware and Japan have begun a regular campaign of observing Comet Hyakutake using an automated 24-inch telescope at Mount Wilson, CA, through the NASA-supported Telescopes In Education (TIE) project.
"We are scheduling one school or group to observe each day of the week," said Gilbert Clark, TIE project manager and organizer of the comet campaign. He expects the observations to continue, weather permitting, through at least part of April, as the comet moves from an early- morning object in the southwest sky to an early-evening object in the northwest sky.
Students will control the telescope and receive their images via telephone lines at their schools, using desktop computers and commercial software. The software package allows them to perform digital image processing to enhance contrast and other features, as is done with spacecraft images. They will send their observation notes and images to the TIE project's World Wide Web page.
A comet is a small, icy body that orbits the Sun in an elongated orbit that can be disturbed by the on-going orbits of the planets. Resembling a "dirty snowball," a comet typically has a relatively tiny nucleus, often less than six miles across. When radiation from the sun warms a comet, ice particles from its nucleus tend to "steam" outwards, creating a large coma or surrounding atmosphere and a tail of material that streams away from the Sun. In some cases, the coma and tail can be thousands or even millions of miles across, offering dramatic viewing opportunities. Comet Hyakutake has the potential to provide just such a spectacle.
According to the Harvard-Smithsonian Center for
Astrophysics, Cambridge, MA, Comet Hyakutake will make the
nearest passage to Earth of any comet since 1983, and the
fifth closest this century.
Comet 1996 B2 Hyakutake Home Page