Seen from outside, Enceladus appears to be like most of its sibling moons: cold, icy and inhospitable.
The Calabash Nebula, pictured here is a spectacular example of the death of a low-mass star like the sun.
Dr. George Carruthers, right, and William Conway, a project manager at the Naval Research Institute, examine the gold-plated ultraviolet camera/spectrograph, the first moon-based observatory that Carruthers developed for the Apollo 16 mission. Apollo 16 astronauts placed the observatory on the moon in April 1972.
This panorama, photographed by an astronaut aboard the International Space Station, shows nearly the full length of Lake Powell, the reservoir on the Colorado River in southern Utah and northern Arizona. Note that the ISS was north of the lake at the time, so in this view south is at the top left of the image.