Officially ice

Oven bakes out water; mission successes lead to longer lander life

The Phoenix Mars Lander has finally “tasted” and “touched” water ice, mission scientists reported. This result, along with other mission successes, has sparked NASA officials to extend the life of the lander, which touched down on the Red Planet May 25. The scientists will have an extra 34 days to learn about the soil and atmosphere of Mars’ polar region.

Detecting the water ice in this latest sample was a surprise, said Phoenix scientist William Boynton of the University of Arizona in Tucson during a July 31 mission press briefing. The Phoenix team has been trying to analyze a sample from a hard layer beneath the topsoil, but delivering such a sample to the Thermal and Evolved-Gas Analyzer, or TEGA, instrument has proven difficult for the past month.

The TEGA ovens are designed to bake samples, identifying components primarily by their melting points as a way to directly detect the presence of certain compounds, such as water ice.

After the last two attempts to deliver a sample to one of the instruments’ remaining ovens failed, the team decided to put a sample of soil taken from just above the ice layer into the instrument. It turned out that the soil contains ice, Boynton, a Phoenix coinvestigator and lead TEGA scientist, announced July 31.

When the oven heated the soil, some of the sample melted at 0° Celsius, the melting point of ice, and the TEGA also detected water vapor during the analysis, Boynton noted.

Satellites orbiting Mars had given scientists their first clues that water ice might exist in the Martian polar regions. But TEGA’s ability to “sniff” out the water ice is the first test that gives direct confirmation that the water ice exists.

“Now, we have finally touched and tasted ice on Mars,” Boynton said, “and I can say it tastes very fine.”

Because of the direct detection of water ice, scientists can move away from proving that this type of ice exists, said Michael Meyer, chief scientist for NASA’s Mars Exploration Program, which is headquartered in Washington, D.C. They can start a phase of research on the Red Planet that includes looking at whether or not the soil-ice layer could have ever supported life, he continued.

Meyer also announced that NASA would provide an additional $2 million to extend the life of the lander through September 30. The original mission to conduct research on Mars was to last 90 days and end in late August. The additional funding will enable the mission’s science team to continue probing the Martian arctic atmosphere and soil for an extra five weeks.

“Phoenix is healthy and the projections for solar power look good, so we want to take full advantage of having this resource in one of the most interesting locations on Mars,” Meyer said.

Because of the extension, the scientists have begun deciding where next around the lander to dig trenches for soil collection. They will also begin to make an even more detailed panorama of the lander’s surroundings in the coming days, they said.

A new panoramic image, released July 31 and made with the lander’s camera, showed a dust dominated terrain that the scientists said shows glints of frost that, based on the recent findings, must be water ice. But when the lander decommissions on September 30, the temperature will have dropped enough for carbon dioxide ice to cover the water ice and dominate this part of the arctic terrain, the scientists noted. The team hopes an even more detailed panoramic image of the Martian terrain might glimpse some of that icy CO2 frosting.

This future composite photo, said Texas A&M University’s Mark Lemmon, lead scientist for the camera that took the photos, will be the scientists’ last, so they’ve dubbed it their “happily ever after pan” of the Martian arctic.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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