Spacecraft Cassini will make its only close flyby of Saturn's odd, two-toned, walnut-shaped moon Iapetus on Sept. 10, at about 1,640 km from the surface, according to mission updates from NASA.
This flyby will be 100 times closer than Cassini's 2004 encounter, and will be the last time the spacecraft will aim its instruments at this moon.
"Iapetus spun fast, froze young, and left behind a body with lasting curves," said Julie Castillo, Cassini scientist at NASA's Jet Propulsion Laboratory.
Iapetus has a ridge of surprisingly large mountains -- the so-called "belly-band" -- that lies directly on top of the equator. The moon also has a distinct difference in the brightness of its leading and trailing hemispheres, one as bright as snow and the other dark as tar.
The irregular shape, the mountain ridge and Iapetus' brightness contrast are among the key mysteries scientists are trying to solve.
An array of Cassini instruments will home in on Iapetus during the flyby. The full menu of objectives includes plans to: characterize the chemical composition of the surface; look for evidence of a faint atmosphere or erupting gas plumes; and map the nighttime temperature of the surface.
This will be the first Cassini flyby of an icy moon, other than Titan, that's close enough and slow enough to perform radar imaging with Cassini's Synthetic Aperture Radar. A large swath of terrain will be covered, including the equatorial ridge and regions of craters and basins. These measurements may provide the height of some of the features.
In coming weeks, scientists will be analyzing data from multiple instruments. Some results of that analysis will be presented at a planetary science conference in Orlando, Fla., in mid-October.
Source: Xinhua
|
Comment
Tell A Friend
Print Format
Save Article