Smooth Patch Beneath Phoenix has Changed
A patch of shiny material visible beneath NASA's Phoenix Mars Lander dubbed "Snow Queen" underwent a striking change in appearance sometime between mid-June and mid-July, the space agency announced today. Now visible are cracks up to about four inches (10 centimeters) in length, a pebble less than one third inch (seven millimeters) in size, and a subtle change in the surface's smooth texture—none of which were seen during the first 20 sols (Martian days) of the mission, Phoenix co-investigator Mike Mellon of the University of Colorado at Boulder said in a statement. The changes call to mind the presumed ice specks that Phoenix observed sublimating (or vaporizing) from trenches dug near the craft. Phoenix got its first gander at Snow Queen on May 31 in what was cautiously described as possible ice exposed by thruster exhaust during landing six days earlier. The Phoenix team discovered the new changes when it checked on Snow Queen on July 9 after last viewing it on June 15. Mellon said the cracks could have formed from repeated expansion and contraction of the surface, or that the exposed layer simply shrank and cracked or that sublimating ice slowly revealed cracks underneath. The small pebble might have broken free of the surface or fallen from somewhere else, he said. Stay tuned for further changes.