The current view August 30, 2010Posted by Simon in Uncategorized.
What’s the current “accepted wisdom” on the Martian meteorite theory? I did a survey of some of the popular and scientific press to see what they’ve said recently, as opposed to when the controversy flared up in 1996. Here’s some samples:
In Australia’s Cosmos magazine, physicist and author Paul Davies said last year that
Bill Clinton faced the world’s media on the White House lawn and announced that NASA had evidence for life on Mars in the form of putative micro-fossils in a Martian meteorite found in Antarctica. Though few scientists today believe the marks really are fossilised microbes, the episode raised awareness of the possibility that fossil organisms could make the journey from Mars to Earth.
Somewhat surprisingly, the New York Times hasn’t mentioned the issue much recently; back in 2004, discussing some research that cast more doubt on the biological origins of the signals in ALH84001, they were critical, but not dismissive of NASA’a claim:
NASA scientists said in 1996 that there was nothing ordinary at all about the rock, ALH84001. It came from Mars, and, they said, showed signs that life once existed there. That contention was in part based on what the scientists said were tiny magnetite crystals found in the rock that were similar in size and shape to those produced by bacteria on Earth. The scientists suggested that the crystals were formed by bacteria that lived on Mars billions of years ago.
But since then, other research has undermined the original findings.
Now, a team from the California Institute of Technology, the Massachusetts Institute of Technology and a Japanese research institution has looked at the rock and cast more doubt.
So, they say, it will be difficult to prove definitively that the crystals are a sign of life.
In 2006, New Scientist ran an article called Top 10: Controversial pieces of evidence for extraterrestrial life, and ALH84001 was number 3:
NASA scientists controversially announced in 1996 that they had found what appeared to be fossilised microbes in a potato-shaped lump of Martian rock.
But since then much of the evidence has been challenged. Other experts have suggested that the particles of magnetite were not so similar to those found in bacteria after all, and that contaminants from Earth are the source of the organic molecules. A 2003 study also showed how crystals that resemble nanobacteria could be grown in the laboratory by chemical processes.
Again, it’s what they’re not saying (that the initial idea was wrong) that’s notable.
Looking through these and other writings, it’s clear that scientists are much more willing to dismiss the NASA claim for evidence of Martian bacteria than the press, who seem cautious about making definitive statements on the issue. Is this because the press is presenting a more objective, balanced view of things? Or is it because they can sell more magazines or newspapers by keeping the debate alive? Something for me to look into….