The media teleconference this morning helped to clarify some of the questions surrounding the latest results from Phoenix. Speculation ran from finding evidence for life to evidence that it was almost impossible. The truth, as usual, is somewhere in between.

The latest finding is of the perchlorate salts in the Martian soil. Or at least the tentative finding, still waiting for confirmation. But as to how this impacts the probability of life, it doesn’t much, either way. While generally toxic, they don’t destroy organics or microbes, etc. as some had suggested. In the Atacama desert in Chile, where they are naturally found in the surface soils, it was previously thought that life coudn’t exist there either, but more recent studies show the soil a bit deeper down to be teeming with microbes and organics. Some types of microbes on Earth even use perchlorates as an energy source.

Also, according to the Phoenix team, it is unlikely to be the “superoxidant” which has been theorized to explain the Viking results in the 1970s (re my previous post), as it is not toxic and reactive enough and does not release oxygen when wetted (as per the Viking experiments) and other reasons.

So, the testing will continue over the next couple months or so (until the north polar ice eventually covers Phoenix in the coming winter), and we will learn more as time progresses. The perchlorates are one more piece of the puzzle, but not the final answer regarding past or present life on Mars by any means.

The media teleconference audio can be heard and downloaded here.

Posted by Paul Scott Anderson on August 5, 2008 at 7:54 pm