On September 24, Cassini made its first close flyby of Saturn's icy moon Tethys. On the 26th, it went by Hyperion, the moon of Saturn that has chaotic rotation because of being tugged at by other moons. Here's a mosaic of Tethys. It's our best view of its south polar region. There's a huge chasm to the lower left. The features look soft because ice does not hold their shapes as well as rock.
This false color pictue of Hyperion made with infrared, green and ultraviolet filters shows its irregular shape and a large circular feature. It's a huge ancient crater eroded by lots of smaller later impacts. If we were there, it'd look redish. It looks like newer craters expose bright icy material and older ones filled in with black stuff. Here's a view of part of the ancient crater rim. Here's a nice view of the edge.
It's interesting how Phoebe is dark with bright material exposed by impacts and Iapetus is half bright and half dark and Hyperion is bright with dark material exposed by impacts. Phoebe is the furthest of those three from Saturn, Hyperion is the closer of those three and Iapetus is in between.
To see more pictures, this site can show you the raw images. Just choose Tethys or Hyperion and narrow angle and don't worry about the time and distance options and press search images and it will show you the most recent 500 images on several tens of pages. The next close Tethys flyby will be in 2007 and I don't know of any more planned close Hyperion flybys. So the recent images won't be displaced down the list of 500 images very far for a while, making them easy to find.
Tethys is about 1000 km across and Hyperion is 225 to 360 km across.
This false color pictue of Hyperion made with infrared, green and ultraviolet filters shows its irregular shape and a large circular feature. It's a huge ancient crater eroded by lots of smaller later impacts. If we were there, it'd look redish. It looks like newer craters expose bright icy material and older ones filled in with black stuff. Here's a view of part of the ancient crater rim. Here's a nice view of the edge.
It's interesting how Phoebe is dark with bright material exposed by impacts and Iapetus is half bright and half dark and Hyperion is bright with dark material exposed by impacts. Phoebe is the furthest of those three from Saturn, Hyperion is the closer of those three and Iapetus is in between.
To see more pictures, this site can show you the raw images. Just choose Tethys or Hyperion and narrow angle and don't worry about the time and distance options and press search images and it will show you the most recent 500 images on several tens of pages. The next close Tethys flyby will be in 2007 and I don't know of any more planned close Hyperion flybys. So the recent images won't be displaced down the list of 500 images very far for a while, making them easy to find.
Tethys is about 1000 km across and Hyperion is 225 to 360 km across.