Dispatches from Mars: Interpreting the News from the Red Planet

Frozen water, safe soil, images of treadmarks in red, granular soil: almost every day brings new test results or stunning photographs from the Phoenix exploratory craft that landed on Mars a few weeks ago.

Washington State University astrobiologist Dirk Schulze-Makuch is following the news along with the rest of us. Although he is not directly involved with the Phoenix mission, he has written extensively about the prospects for life on other planets. His 2004 book, “Life in the Universe: Expectations and Constraints,” addressed some of the major assumptions about the conditions necessary for life.

Schulze-Makuch said the Phoenix results so far largely confirm what was already known from other lines of evidence. The finding that the Martian soil is slightly alkaline is “a little bit surprising,” he said, but the presence of water ice and the lack of toxic materials in the soil are not.

“We knew there was water ice there, but it’s nice to get the confirmation,” he said. “The more exciting thing is that the instruments work and they got soil samples.”

Schulze-Makuch cautioned against expecting the mission to send back images of Martian microbes. He said Phoenix might find chemical traces of life, but is not likely to find living things themselves. Even if a sample contained organisms, the likelihood that any of them would appear within the field of view of Phoenix’s microscope is very small, he said.

“Even on Earth, if you take a microscope and look at soil samples, you have to search and search to find something.”

Nevertheless, the successful deployment of the lander’s sampling arms and cameras, and the completion of the initial chemical tests, bode well for the rest of the mission.

“The encouraging thing is that it all works,” he said. He added that he is looking forward to learning the results of further tests over the next several weeks.

Schulze-Makuch is available to talk about the Phoenix results and the search for life on other planets. He can be reached at 509/335-1180 or dirksm@wsu.edu.

For more about his book, see http://researchnews.wsu.edu/physical/80.html. The second edition of the book is scheduled for release in September.