Mars Lander Prepares for Icy Sample

This panorama mosaic of images was taken by the Surface Stereo Imager on board NASA's Phoenix Mars Lander. This mosaic documents the midnight sun during several days of the mission. (Image credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University)

NASA's Phoenix Mars Lander is one step closer to analyzing a sample of the rock-hard layer of ice underneath the Martian dirt where the spacecraft touched down two months ago.

Overnight Tuesday to Wednesday, Phoenix used its robotic arm to scrape the top of the icy layer in the trench informally known as Snow White.

"We are monitoring changes between the scrapes," said Doug Ming of NASA Johnson Space Center, Houston, the team's science lead for Sol 58 plans. "It appears that there is fairly rapid sublimation of some of the ice after scraping exposes fresh material, leaving a thin layer of soil particles that had been mixed with the ice. There's a color change from darker to bluer to redder. We want to characterize that on Sol 58 to know what to expect when we scrape just before collecting the next sample."

Within a few days, the team plans to collect a sample from the icy layer and deliver it to Phoenix's Thermal and Evolved-Gas Analyzer (TEGA). TEGA heats up the samples in its tiny ovens and then analyzes the vapors given off to determine the soil's composition.

"For the next sample, we will be operating the instrument earlier in the morning than we have before," said William Boynton of the University of Arizona, lead scientist for TEGA. "It will be almost the coldest part of the day, because we want to collect the sample cold and deliver it cold."

Phoenix will also check for dirt devils during Sol 58. NASA's Mars Rover Spirit has also imaged dirt devils south of Mars' equator.

Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.