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Possible Evidence of Martian Bacteria
half-seas-over writes "NASA issued a very interesting press release today. It highlights a recent study that compared tiny magnetite crystals in the Allan Hill meteorite to similar magnetite crystals that are created here on Earth by bacteria (who use the magnetite as a compass). The study (abstract available here (PDF) from this site) uses fairly strict criteria to determine that 25% of the magnetite content of the meteorite was created by ancient (>3.9Gyr ago) martian bacteria... either that or there is some strange natural process that makes very pure, isolated magnetite crystals that we haven't imagined or seen on Earth which is present on Mars. We'll have to wait and see what happens next, 'extraordinary claims require extraordinary evidence' -Carl Sagan."
Not true: very little (if any) of the life on Mars findings have been proven or disproven. All that is happening is that some scientists are presenting their evidence that supports the hypothesis that life has existed or even does exist on Mars. Other scientists are scrutinising this evidence and poking holes in their analyses. This is part of the scientific process and only to be expected. What is needed is a new form of data. We can argue about magnetite in Mars meteorites for years but it probably won't solve anything. What we need is a fresh sample, that hasn't been superheated on impact and re-entry.
How all this is portrayed in the media is often misleading and, yes, that is sometimes the fault of the scientists as much as the science journalists. The truth is that the media tends to dumb down science for the general public in the belief that real science is too boring for them. Whether this is justified or not is a matter of opinion.
Scientific press releases can be a good way to get research funding. It is also a very dangerous game to play, as scientists are often misquoted to their expense.
-Karl
Dr Karl Mitchell
Planetary Science Research Group
Environmental Science Dept.
Lancaster University
UK
If you just once bothered to read the damn study you just MIGHT have enough brain capasity to note that "compass theory" comes from a FACT that some of very-much-real-and-existing EARTH bacteria create same kind of "compass crystals".
AND that those created by bacteria are notably DIFFERENT from those that result from chemical reactions in non-living things. AND that the one in Martian rock resemble those created by Earth-bacteria, and not those randomly formed ones.
If the crystals were not formed by bacteria, the most likely cause is natural geological or chemical processes. Those should be similar here and on Mars (although with different ratios of chemicals and differing gravity). Look at Chapter 3 of "Paleomagnetism: Magnetic Domains to Geologic Terranes" for details on formation of geologic magnetic materials.
In the press release we read " new evidence confirming that 25 percent of the magnetic material in the meteorite was produced by ancient bacteria on Mars. ... This means that
one-quarter of the magnetite
crystals ... in Martian meteorite
ALH84001 require the intervention of biology to explain their
presence.
"
The words "confirm" and "require" are very strong, indeed.
However, in the abstract of the scientific report we read something quite different: " On Earth such ...
magnetites are known to
be produced by magnetotactic bacteria. We suggest that the observation ...
are [sic] both
consistent with, and in the absence of terrestrial inorganic analogs,
likely formed by biogenic processes."
So, the scientists suggest that something is consistent with a proposition, and the press-releasers convert that into confirmation of the proposition.
Sure, scientists' language often needs to be modified for public consumption, but here we have a case of changing the entire thrust of the story.
This sort of mistake would be unacceptable from a high-school science student, and that makes me wonder whether this exaggerating rewriting might have been deliberate. I remember a story of crying "wolf" ...
'extraordinary claims require extraordinary evidence' not carl.
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