Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

Cassini rocks Rhea rendezvous

Scientists will use the data to deduce how often tiny meteorids bombard the saturnian moon’s surface, among other things.
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.

Craters-on-Rhea
This raw image 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. NASA/JPL/SSI
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.

0

JOIN THE DISCUSSION

Read and share your comments on this article
Comment on this article
Want to leave a comment?
Only registered members of Astronomy.com are allowed to comment on this article. Registration is FREE and only takes a couple minutes.

Login or Register now.
0 comments
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
BoxProductcovernov

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook

Loading...