Phoenix ready to "bake and sniff" soil samples on Mars

William Atkins
Saturday, 07 June 2008 19:36

Science - Space

NASA announced that the Phoenix Mars Lander's robotic arm is ready to dump a sample of Martian soil into an open door of the Thermal and Evolved Gas Analyzer (TEGA).

Less than a scoopful (about seven tablespoons) of the sample will soon be analyzed after being taken from an area called "Baby Bear."

The Baby Bear trench, located on the north side of the Lander, is about 3.1 inches (9 centimeters) wide.

The robotic arm of the Phoenix Mars Lander dug into the Martian soil on Thursday, June 5, 2008 (Martian Day 11), after making several practice attempts earlier in the week at the trench called "Dodo."

When it dug into the Baby Bear trench the scoop on the end of the robotic arm picked up a sample of clumpy, reddish-colored material from the top 0.8 to 1.6 inches (2 to 4 centimeters) of the ground.

A light-toned (whitish) clod of soil from the crusted surface was also included in the sample.
 

Commands from Earth were then sent to NASA’s Lander late on Friday, June 6th to have its robotic arm dump the sample into an opened door of one of eight ovens on the TEGA instrument, which is located on the deck of the spacecraft.

University of Arizona professor Peter Smith, the principal investigator for the mission, stated, “It's looks like a good sample for us. Over the next few days, and it may be as much as a week, the TEGA instrument will be analyzing this sample." [University of Arizona, LPL, Phoenix Mars Mission: “NASA Mars Lander Scoops First Soil Sample For Laboratory Analysis”]

Smith added, "This is really an important occasion for us, to be poised to make a measurement for the first time of the polar soil that will tell us how much water is in the soil, and secondly what the minerals are that make up the soil.” [AFP: “Mars probe Phoenix digs up first sample of Martian soil”]

The TEGA instrument will first assess the atmosphere of Mars, and then analyze the sample. It will seal the sample inside the oven by closing its door, and then "bake" it by gradually increasing the temperature to about 1,832 degrees Fahrenheit (1,000 degrees Celsius).

The heat from the oven will causes gases to be expelled. They will be analyzed by a mass spectrometer. It will measure the isotope ratios for hydrogen, carbon, oxygen, nitrogen, and other gases. The mass spectrometer is able to detect values as low as ten parts per billion.

The TEGA will then "sniff" the soil sample to assess its volatile ingredients, such as carbon, hydrogen and oxygen, nitrogen, and various minerals.

What do they hope to find? Please read on.