Valleys of Enceladus

Cassini made its closest flyby of Saturn's mysterious ice moon Enceladus on Tuesday, snapping pictures as it whizzed by at 40,000 mph. The valleys are cracks in the ice that covers the small moon. Scientists believe the cracks are caused by liquid water under the ice.

This flyby showed that the jets of water vapor that Cassini discovered emerge from these cracks.

This picture was taken 545 miles above the surface with a resolution of about 20 feet per pixel. The lumpy objects all over the hills are said to be house-sized ice boulders, but I dunno. From this angle they look like trees dotting an arid, mountainous terrain. Every answer begets new questions.