Wednesday, June 11, 2008

NASA’s Phoenix Lander has begun to cook a scoop full of Martian soil. For reasons unknown to scientists, and after several seemingly unsuccessful attempts to break up the soil, a large amount was discovered to have passed through a screen leading to an on board oven.

“We have an oven full. It took 10 seconds to fill the oven. The ground moved,” said Phoenix co-investigator Bill Boynton, a researcher at the University of Arizona located in Tucson, Arizona.

The lander’s Robotic Arm delivered a partial scoopful of clumpy soil from a trench informally called “Baby Bear” to the number 4 oven on its TEGA (Thermal and Evolved Gas Analyzer) last Friday, June 6. NASA observed the method and reported that no soil had passed through the screens over the TEGA. The screen is to prevent larger bits of soil from clogging the narrow port to each oven so that fine particles fill the oven cavity, which is no wider than a pencil lead. The oven’s goal is to vaporize any ice or water that may be present in the soil. Minerals may also burn off and scientists say that vapors from anything that evaporates or vaporizes will be tested and analyzed.

After some debate, NASA decided to ‘shake’ the soil in hopes that it would break up the larger particles. To much disappointment after six tries using this method, only a few particles got through the screen. Scientists then ordered one last shake of the soil “in the off chance we might get lucky,” stated Boynton.

After a few days of troubleshooting, NASA looked back at the soil and discovered that, for an unknown reason, a large amount of soil had fallen through the screen and was ready for inspection by the TEGA. Boynton states that it is possible that the oven might have filled because of the cumulative effects of all the shaking, or because of changes in the soil’s cohesiveness as it sat for days on the top of the screen.

“There’s something very unusual about this soil, from a place on Mars we’ve never been before. We’re interested in learning what sort of chemical and mineral activity has caused the particles to clump and stick together,” Boynton commented.

Phoenix was originally ordered to put off using its TEGA until scientists came up with a solution to the clodded soil. It had been rescheduled to take readings of the Martian climate such as temperature and wind speed, and also to analyze a soil sample using the optical microscope, or MECA (Microscopy, Electrochemistry, and Conductivity Analyzer) on June 12. Scientists say that those tasks are still scheduled to take place. Pictures and results from that sample are expected to arrive on Thursday June 12, while the oven samples will take a few days to analyze.

“The dirt finally did start to flow and we actually got a full oven, so that problem is now behind us. We’re hopeful that some time in the next few days we’ll close the oven and begin the analysis process,” added Boynton.