RocketSTEM Issue #7 - May 2014 | Page 36

Odd world: This stunning false-color view of Saturn’s moon Hyperion reveals crisp details across the strange, tumbling moon’s surface. The view was obtained during Cassini’s very notably reddish tint when viewed in natural color. Cassini scientists think that Hyperion’s unusual appearance can be attributed to the fact that it has an unusually low density for such a large object, giving it weak surface gravity and high porosity. These characteristics help preserve the original shapes of Hyperion’s craters by limiting the amount of impact ejecta coating the moon’s surface. Impactors tend to make craters by compressing the surface material, rather than blasting it out. Further, Hyperion’s weak gravity, and correspondingly low escape velocity, means that what little ejecta is produced has a good chance of escaping the moon altogether. Credit: NASA/JPL/Space Science Institute Epic Odysseus: With an epic size, Odysseus Crater stretches across a large northern expanse on Saturn’s moon Tethys. Odysseus Crater is 450 kilometers, or 280 miles, across. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Feb. 14, 2010. The view was obtained at a distance of approximately 178,000 kilometers (111,000 miles) from Tethys. Image scale is about 1 kilometer (about 3,485 feet) per pixel. Credit: NASA/JPL/Space Science Institute 34 34 www.RocketSTEM .org