Proctor Crater Sand Dunes Size:45" x 30" (114 cm x 76 cm) This portrait looking down on

This portrait looking down on Saturn and its rings was created from images obtained by NASA's Cassini spacecraft on Oct

The star-birthing frenzy in 30 Doradus may be partly fueled by its close proximity to its companion galaxy

many unusual features unique to Mars are visible

At the heart of the artwork is a set of four monstrously massive stars

They are overlaid on this image to give a scale to Hubble's very narrow view on the heavens

Proctor Crater Sand Dunes Size:45" x 30" (114 cm x 76 cm) This portrait looking down onThis view from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter shows two classes of aeolian bedforms within Proctor Crater. The relatively bright, small ridges are ripples. From their study on Earth, and close up examination by the MER rovers (roving elsewhere on Mars), we know that ripples are composed of fine sand (less than 200 microns in diameter) or fine sand coated with coarser sand and