Debris blasted off the satellite Amalthea in high-speed collisions
with interplanetary meteoroids will start with slightly inclined orbits
like that of Amalthea (yellow lines), forming a slender tube around
the satellite trajectory. These orbital paths are not, however, stationary
in space but instead wobble about Jupiter's equator like a giant hula-hoop,
keeping the same tilt off the equator but continually changing their
orientations at rates that differ slightly depending on orbital size and
shape. (Two orbits are shown at top.) Thus within a few years of the impact
that formed the debris tube, the tube smears out into a thin cylindrical shell
at Amalthea's orbital distance (web of lines shown in bottom panel).
When viewed from the side within the equatorial plane, this hoop appears
to be a thin rectangle. As the particles move to the top of their paths
around Jupiter and back down, they pause at their greatest heights
off the equatorial plane. Since all the debris particles have the same
orbital tilts, this pausing leads to a ring that is slightly denser
at the edges than in the equatorial plane. Following the early stages
of evolution shown here, the particles will eventually drift inwards
as they absorb sunlight, and fill a flat washer-shaped disk.Debris blasted off the satellite Amalthea in high-speed collisions
with interplanetary meteoroids will start with slightly inclined orbits
like that of Amalthea (yellow lines), forming a slender tube around
the satellite trajectory. These orbital paths are not, however, stationary
in space but instead wobble about Jupiter's equator like a giant hula-hoop,
keeping the same tilt off the equator but continually changing their
orientations at rates that differ slightly depending on orbital size and
shape. (Two orbits are shown at top.) Thus within a few years of the impact
that formed the debris tube, the tube smears out into a thin cylindrical shell
at Amalthea's orbital distance (web of lines shown in bottom panel).
When viewed from the side within the equatorial plane, this hoop appears
to be a thin rectangle. As the particles move to the top of their paths
around Jupiter and back down, they pause at their greatest heights
off the equatorial plane. Since all the debris particles have the same
orbital tilts, this pausing leads to a ring that is slightly denser
at the edges than in the equatorial plane. Following the early stages
of evolution shown here, the particles will eventually drift inwards
as they absorb sunlight, and fill a flat washer-shaped disk.
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission
for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted
on the World Wide Web, on the Galileo mission home page at URL
http://galileo.jpl.nasa.gov/.
Background information and educational context for the images can be found at:
http://www.jpl.nasa.gov/galileo/sepo.
