Still, the presence of ice in the latest sample was a surprise.
Efforts to acquire larger ice samples for TEGA have been hampered by collection problems—most recently when two promising ice loads simply stuck in the scoop and could not be transferred to the instrument.
(See "Mars Lander Stymied by Ice; Like 'Scraping a Sidewalk'" [July 11, 2008].)
Unable to collect ice from the solid ice layer, the team decided to analyze a soil sample from just above it.
Surprisingly, the soil turned out to be made of about one percent water ice.
"Now we are starting analysis of what turns out to be an icy soil," Boynton said.
Tests on the Martian soil could reveal whether it has ever been in contact with melted, liquid water—a key indicator that the area might have once been habitable.
The extended mission also creates exciting opportunities for Phoenix's onboard weather station.
The apparatus uses a skyward-pointing laser beam to profile the dust and clouds in the Martian atmosphere and to measure atmospheric pressure, temperature, and winds.
So far Phoenix has experienced the relatively benign weather of Mars's late spring and summer—but that is expected to change soon.
"For atmospheric science, the longer [the mission] lasts, the better, so we can begin to understand the seasonal changes," said Quebec-based Victoria Hipkin of the Canadian Space Agency.
"We're expecting to see much more in the way of dust and cloud activity as we go forward."
NASA also released a color, panoramic image of the Phoenix landing site, which had been created by painstakingly downloading and stitching together some 500 pictures.
The shot helps scientists better understand the features of the local, ice-dominated environment, which is covered by the planet's ubiquitous rust-colored dust.
Mark Lemmon, of Texas A&M University, said the lander's Surface Stereo Imager would keep blazing away as the mission continued—revealing seasonal changes on the Martian surface.
"Later in the year more frost will appear, and eventually [we'll see] a winter wonderland of carbon dioxide frost that will [signal] the end of the Phoenix mission in months to come."
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