Phoenix eats dirt
TEGA oven finally full
The Thermal and Evolved-Gas Analyzer (TEGA) aboard NASA's Phoenix Mars lander finally has an ovenful of dirt for anlaysis, following various attempts to shake the "clumpy" Martian soil into the instrument.
The "high-temperature furnace and mass spectrometer" TEGA packs eight miniature ovens, each protected by a filter screen to prevent the entry of particles larger than 1mm. However, the Red Planet's surface resolutely refused to play ball when NASA tried to fill oven number four last Friday, and the infrared beam designed to detect particles falling into the oven showed no activity.
NASA then deployed the "whirligig mechanism that vibrates the screen to help shake small particles through" and vibrated the oven's screen on 6, 8 and 9 June, which resulted in just a few particles surrendering to the chamber. However, NASA yesterday announced the oven was full, although it's not quite sure why, with Phoenix co-investigator Bill Boynton of the University of Arizona offering that it "might have filled because of the cumulative effects of all the vibrating, or because of changes in the soil's cohesiveness as it sat for days on the top of the screen".
Nonetheless, Boynton declared: "We have an oven full. It took 10 seconds to fill the oven. The ground moved."
Phoenix Principal Investigator Peter Smith, of the University of Arizona, said: "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."
While TEGA can now get on with "sniffing" the soil to "assess its volatile ingredients, such as water", Phoenix's tasks today comprise "sprinkling Martian soil on the delivery port for the spacecraft's Optical Microscope and taking additional portions of a high-resolution color panorama of the lander's surroundings". ®