Image of the Day: Saturn's Rhea Up Close and Personal

NASA's Cassini spacecraft has successfully completed its closest flyby of Saturn's moon Rhea, returning raw images of the icy moon's surface.

Pictures of the Rhea surface taken around the time of closest approach January 10 at 10:53 p.m. PST show shadowy craters at a low Sun angle. A portrait of bright, icy Rhea also captures Saturn's rings and three other moons clearly visible in the background.

Images obtained by Cassini's imaging science subsystem show an old, inert surface saturated with craters, just like the oldest parts of Earth's Moon. But there appear to be some straight faults that were formed early in Rhea's history, which never developed the full-blown activity seen on another of Saturn's moons, Enceladus.

The flyby of Rhea also presented scientists with their best available chance to study how often tiny meteoroids bombard the moon's surface. Scientists are now sifting through data collected on the close flyby by the cosmic dust analyzer and the radio and plasma wave science instrument. They will use the data to deduce how often objects outside the Saturn system contaminate Saturn's rings, and to improve estimates of how old the rings are.

Scientists using Cassini's fields and particles instruments are also looking through their data to see if they learned more about Rhea's thin oxygen and carbon dioxide atmosphere and the interaction between Rhea and the particles within Saturn's magnetosphere, the magnetic bubble around the planet.

At closest approach, Cassini passed within about 43 miles (69 kilometers) of the surface.

The raw image at top of page was obtained by NASA's Cassini spacecraft of Saturn's moon Rhea shows craters in an area between day and night on the icy moon. Cassini's wide-angle camera was about 100 miles (200 kilometers) away from Rhea's surface when the image was taken. The bright spot to the right is likely a cosmic ray hit.

The Daily Galaxy via NASA/JPL/SSI

 

Comments

[Majhar khan]

I am a bsc student i have most intrest in physics so pls send me some imp tips.

[J. Major]

This was a great flyby by Cassini! 43 miles is an incredibly close pass. I have some more images from it up on my site here as well: http://lightsinthedark.wordpress.com/2011/01/12/a-close-pass/

[wiem]

When image is rotated left 90 degrees, with black 'sky' in top right corner, the craters are far easier to identify. ;-)