NASA says Phoenix spacecraft may have landed on ice

Sunday, June 1, 2008

A view from under the lander showing the layer of possible ice exposed by Phoenix's thrusters.
Image: NASA/JPL.

According to NASA, new images received from the Phoenix lander on Mars shows a possible layer of ice on its landing site. Scientists received the images on Friday May 30 from the craft's robotic arm camera. The image was taken on the fifth Martian day, or Sol 5.

Scientists say that as Phoenix landed, the exhaust from its thrusters cleared away a three to four inch layer of Martian soil which exposed a flat layer of a white substance, that NASA says could be ice. The image shows the white layer which is shiny and smooth.

"It's the consensus of all of us that we have found ice. We were expecting to find ice within two to six inches of the surface. The thrusters have excavated two to six inches and, sure enough, we see something that looks like ice. It's not impossible that it's something else, but our leading interpretation is ice," said top Phoenix investigator at the University of Arizona in Tucson Peter Smith.

One exposed edge of the underlying material was seen in Sol 4 images, but the newer image reveals a greater extent of it. The abundance of excavated smooth and level surfaces adds evidence to a hypothesis that the underlying material is an ice table covered by a thin blanket of soil. Tests will be performed on the soil and surrounding area to determine exactly what the substance is.

"We could very well be seeing rock, or we could be seeing exposed ice in the retrorocket blast zone. We'll test the two ideas by getting more data," stated Ray Arvidson, one of the mission investigators.

Phoenix is searching for evidence of water and microbial life on Mars. Its mission is to determine Mars's ability or inability to host life and hold water. The Phoenix lander uses a robotic arm to dig through the protective top soil layer to the alleged water ice below and ultimately bring both soil and water ice to the lander platform for sophisticated scientific analysis.