Mars

A Piece of Mars: This 480x270 m (0.3x0.17 mi) scene shows the contact between two very different terrains. On the left is a bright surface with polygonal cracks (characteristic of periglacial terrain - this is at a high latitude). On the right is a dark rippled sand sheet that superposes the polygonally-cracked surface. The long meandering furrows might be the beginnings of polygonal cracking in the sand, which might expand if wind doesn't erase them. (HiRISE PSP_006473_1125, NASA/JPL/Univ. of Arizona) read more ❯

A piece of Mars: Several years ago, a guy named Richard Hoagland claimed that some parallel linear features on Mars looked like the ridges of a transparent earthworm, calling these things "glass worms". Phil Plait debunked it nicely, but Hoagland stood his ground. He hasn't said much about them lately, has he? Here's why. New images show that, as scientists originally thought, these are nothing more than windblown ripples in the floors of channels, just like the many thousands of ripples seen all over Mars. Go science! (HiRISE ESP_035634_2160, NASA/JPL/Univ. of Arizona) read more ❯