NASA's Phoenix Mars Lander scoops up soil sample for lab analysis

Washington, August 23 : NASA's Phoenix Mars Lander has scooped up a soil sample from an intermediate depth between the ground surface and a subsurface icy layer and delivered it to a laboratory oven on the spacecraft for analysis.

The robotic arm on Phoenix collected the sample, dubbed "Burning Coals," from a trench named "Burn Alive 3."

In part of the trench, the arm had dug down to the hard, icy layer about 4 centimeters (1.6 inches) below the ground surface.

Next to that deeper part, it left a bench of material about 1 centimeter (0.4 inch) above the icy layer, and then collected about one-fourth to one-half a teaspoon of loose soil from that benchtop into the scoop.

Early On August 21, downlinked information from Phoenix confirmed to the mission's science and engineering team that the arm had delivered some of that sample through the doors and almost completely filled cell number 7 of the lander's Thermal and Evolved-Gas Analyzer (TEGA).

TEGA won't begin heating an oven until it senses that oven is full. So, the science team will command the oven door to close and the cell will begin heating the sample to low temperature, to 35 degrees Celsius, or 95 degrees Fahrenheit.

The purpose of the low temperature heating is to look for ice in the sample.

The next step is a middle temperature heating process, which heats the sample to 125 degrees Celsius, or 257 degrees Fahrenheit. This step assures that the sample is dry.

The last heating occurs at 1,000 degrees Celsius, or 1,832 degrees Fahrenheit.

The gases given off during these heating stages helps the science team to determine the specific properties of the Martian soil.

"We are expecting the sample to look similar to previous samples," said William Boynton of The University of Arizona, lead scientist for TEGA. "One of the things we'll be looking for now is an oxygen release indicative of perchlorate," he added.

According to Ray Arvidson, a leader of Phoenix science team activities, "We want to know the structure and composition of the soil at the surface, at the ice and in-between to help answer questions about the movement of water - either as vapor or liquid - between the icy layer and the surface."

ANI