September 09, 2008
The next soil sample that NASA's Phoenix Mars Lander will deliver to its deck instruments will go to the fourth of the four cells of Phoenix's wet chemistry laboratory, according to the Phoenix team's current plans. The chosen source for that sample is from the "Snow White" trench on the eastern end of the work area reachable with Phoenix's robotic arm. In July that trench yielded a sample in which another analytical instrument, the Thermal and Evolved Gas Analyzer (or TEGA), confirmed the presence of water ice.
One of the three cells previously used on the wet chemistry laboratory also analyzed a sample from Snow White. The wet chemistry laboratory mixes Martian soil with purified water brought from Earth as part of its process for identifying soluble nutrients and other chemicals in the soil. Scientists have used it to determine that the soil beside the lander is alkaline and to identify magnesium, sodium, potassium, chloride and perchlorate in the soil.