Phoenix at work on Mars, Sol 69 (app. Aug 4)/NASA
Stung by allegations that NASA stifled one science team while planning a secret White House briefing on a finding of life on Mars, the Mars Phoenix Lander Team today opened yet another window on their science processes.
"We want to set the record straight...we're not with-holding anything" NASA spokesman Dwayne Brown declared at a special press briefing this afternoon. Participants included Michael Meyer, chief scientist, Mars Exploration Program, NASA HQ; Peter Smith, Phoenix principal investigator, University of Arizona; Michael Hecht, science lead for the Microscopy, Electrochemistry and Conductivity Analyzer, Jet Propulsion Lab; and William Boynton, science lead for the Thermal and Evolved-Gas Analyzer, University of Arizona.
The team tackled what Smith called "outrageous" stories launched by an Aviation Week article alleging secrecy about Phoenix findings. Fueled by what the team called "speculation," the stories took on a life of their own, briefly obscuring the actual science involved in understanding the finding of perchlorate in the artcic region of Mars.
Hecht noted that one portion of the analysis process now in work includes further analysis of samples to determine why two different instrument suites, MECA and TECA, gave what seem to be contradictory resuls about the presence of perchlorate. The team will re-sample and test.
So far, the team believes that the perchlorate will be one of these types--magnesium, calcium or iron--or perhaps a combination. They're also carefully analyzing any possibility that the Delta II rocket may have left any trace elements on the Lander itself, a possibility Smith called "remote."
The perchlorate, an oxidizer, is not necessarily the death knell for life of some sort, or habitability, on Mars, the team said. It's simply an element, and one that occurs on Earth, that must be analyzed in terms of the total Martian environment.
"There are a large number of plants that concentrate perchlorate" on Earth, Phoenix co-investigator Sam Kounaves said, comparing the process to that of nitrates in Earth soil. The Tufts University researcher also noted that some species of bacteria on Earth live in soil containing perchlorate.
What's ahead: weeks of rigorous scientific protocols, collection, analysis, re-collection, re-analysis, and peer review, all performed via instruments 400 million miles away. To add to the challenge, the team is up against a tight deadline. Although the Phoenix Lander mission was extended briefly, the team only has about five more weeks for this phase of their Mars exploration mission.
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