NASA Spacecraft Finds More Ice on Mars

Images taken by NASA’s Mars Reconnaissance Orbiter (MRO) of new impact sites on Mars reveal frozen water just under the surface, NASA reports. Team members from NASA’s Jet Propulsion Laboratory, which manages the mission, held a media teleconference on Thursday discussing the findings. Although water-ice has been detected on Mars previously, most recently by the Phoenix lander, scientists were surprised by the location and purity of the recently discovered ice.

For the past few months, the team has been studying images captured by instruments aboard the MRO, including the High Resolution Imaging Science Experiment (HiRISE) camera, which showed evidence of a material at the bottom of several new craters that “looked a lot like ice,” said Shane Byrne of the University of Arizona, member of the HiRISE team. At one of these sites, situated between the northern pole and the equator, they found a larger area of bright material and used the MRO’s Compact Reconnaissance Imaging Spectrometer (CRISM) to determine its composition. “We saw a beautiful water ice spectral signature; no doubt about it: it was water ice,” said Selby Cull, from the Washington University of St. Louis and part of the CRISM team. During further observations, the ice dissipated at a faster rate than expected, leading them to conclude that the ice was about 99 percent pure, a fact that also took them by surprise. Previously, NASA’s Phoenix Lander had uncovered two kinds of ice with varying purity further north, leading scientists to expect dirtier ice as the norm.

The finding was taken to be a “relic of a previously wetter climate,” said Byrne and sheds light on the more recent changes of the Martian climate, which could point to further understanding of climate change on Earth. Scientists noted that NASA’s Viking 2 spacecraft – one of the earliest successful Mars lander programs – landed about 360 miles from the observed area in 1976. If the soil sampling arm on Viking had been able to dig down just 4 inches deeper it might have hit upon the ice as well. “We would have liked to have had that information about Mars in the last 30 years,” said Selby.

The team found ice exposed within a total of five new craters of depths varying between 1.5 feet and 8 feet. The findings are reported today in the journal Science (subscription required).