NASA Phoenix Mars Lander Confirms Frozen Water

Scientists relishing confirmation ofwater ice near the surface beside NASA’s Phoenix Mars Lander anticipate even bigger discoveries from the robotic mission in the weeks ahead. Phoenix has spotted the sublimation of probable water ice in a trench excavated by its robotic armby comparing two photos taken on the 21st and 25th days of the mission, aka Sols 20 and 24 (15 and 19 June).

The mission has the right instruments for analyzing soil and ice to determine whether the local environment just below the surface of far-northern Mars has ever been favorable for microbial life. Key factors are whether the water ever becomes available as a liquid and whether organic compounds are present that could provide chemical building blocks and energy for life. Phoenix landed on May 25 for a Mars surface mission planned to last for three months.

These color images were acquired by NASA’s Phoenix Mars Lander’s Surface Stereo Imager on the 21st and 25th days of the mission, or Sols 20 and 24 (June 15 and 19, 2008).

These images show sublimation of ice in the trench informally called “Dodo-Goldilocks” over the course of four days.

In the lower left corner of the left image, a group of lumps is visible. In the right image, the lumps have disappeared, similar to the process of evaporation.

The key new evidence is that chunks of bright material exposed by digging on June 15 and still present on June 16 had vaporized by June 19. “This tells us we’ve got water ice within reach of the arm, which means we can continue this investigation with the tools we brought with us,” said Mark Lemmon of Texas A&M University, College Station, lead scientist for Phoenix’s Surface Stereo Imager camera. He said the disappearing chunks could not have been carbon-dioxide ice at the local temperatures because that material would not have been stable for even one day as a solid.

The disappearing chunks were in a trench to the northwest of the lander. A hard material, possibly more ice, but darker than the bright material in the first trench, has been detected in a second trench, to the northeast of the lander. Scientists plan next to have Phoenix collect and analyze surface soil from a third trench near the second one, and later to mechanically probe and sample the hard layer.