Random Acts of Verbiage

In news today, “Bright Chunks at Phoenix Lander’s Mars Site Must Have Been Ice” (!!) This is big news! It was known that water ice exists on Mars, but now there is direct evidence for it. The image at right shows “sublimation of ice in the trench informally called “Dodo-Goldilocks” over the course of four days.”

The white stuff we see on Mars’ polar regions many people think of as being ice. Well that is correct, but not water ice. The white we see is carbon dioxide ice (dry ice). It was assumed that there was a layer of water ice underneath the dirt and carbon dioxide, but until now it had been unproved. The image shows a region that had been un-earthed (un-marsed?) by the Phoenix’s scoop. Initially there were some white chunks that could have been either salt or water ice. A few days later the same spot was imaged and the spots were gone indicating that the ice had sublimed (which salt cannot do). Because carbon dioxide and dihydrogen oxide sublime at different pressures and temperatures, they know that it is water.

Pretty awesome, eh?

Reference:
Phoenix Mars Mission @ The University of Arizona: Bright Chunks At Phoenix Lander’s Mars Site Must Have Been Ice
Phoenix Mars Lander @ NASA: Disappearing Ice
Two cool twitter posts: “Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!” and “Whoohoo! Was keeping my eye on some chunks of bright stuff & they disappeared! Sublimated! So it can’t be salt, it’s ice.“