Space Topics: Saturn
RHEA
The Biggest Icy Moon of Saturn
Saturn's Moon Rhea
Rhea, like Dione, has an ancient, cratered, icy surface, split by delicate
bright-walled fractures. Credit: NASA/JPL/Space Science Institute
|
Size: 1,538 kilometers - 2nd largest moon
of Saturn
Orbital radius: 527,040 kilometers - 8.74 Saturn radii - within
the E ring
Orbital period: 4.518 days - about 2/7 of Titan's
Discovery: 1672 by Giovanni Domenico Cassini
Rhea is the largest of Saturn's medium-sized icy moons. From a distance,
Rhea looks similar to Tethys with its wispy grooves and flat-floored craters.
Close up, Rhea shows itself one of the most heavily cratered places in
the Solar System. Its craters tend to be polygonal in shape, having straighter
rather than curved sides, possibly indicating the orientations of preexisting
fractures in Rhea's outer crust that are too fine to see in currently available
images. Features on Rhea are named for people and places from creation
myths around the world.
Flybys of Rhea
Cassini
January 16, 2005 at 15:51 UTC
“0CRH” nontargeted flyby
Closest approach altitude 153,500 kilometers (95,400 miles)
Cassini
April 14, 2005
“O6RH” nontargeted flyby
Closest approach altitude approximately 240,000 kilometers (150,000 miles)
Future Flybys
Cassini
January 16, 2005 at 15:51 UTC
“18RH” targeted flyby [R1]
Closest approach altitude 500 kilometers (311 miles)
Map of Rhea
Global map of Rhea (simple cylindrical projection)
Global map centered at 180 degrees longitude (the anti-Saturnian point). The map is 2,048 pixels wide, and Rhea's diameter is 1,528 kilometers, so the map resolution is 2.34 kilometers per pixel at the equator. A larger and more up-to-date version may be available at Steve Albers' website.
Credit: NASA / JPL / Space Science Institute / Steve Albers
|
|
[ what is this? ]