Saturday, July 17, 2004

More From Cassini

There was a flurry of stunning pictures from Cassini in the beginning of July but then nothing for the past two weeks. Why? Shortly after Cassini achieved Saturn Orbit Insertion, the whole Saturnian system disappeared behind the Sun as viewed from Earth. Communication with the probe was impossible during this time. Recently, Saturn emerged from behind the Sun and NASA was able to start downloading data from Cassini again.
Dark and bright Iapetus
Take a look at one of these new images, a view of Saturn's bizarre moon Iapetus. It sort of looks like our moon but there is something quite odd about Iapetus. The dark area in this picture is not shadow! One side of Iapetus is very bright, the other side is caked with darker material. No one knows for sure what causes this difference of appearance. One theory is since that side of Iapetus is the leading edge in its orbit around Saturn, it is collecting debris. Much like running your finger across a dusty table, Iapetus may have plowed up all the junk that crossed its orbit. Neat!