Life on ancient Mars?

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Los Angeles Times Feb 27, 2001

New evidence points to ancient life on Mars

By Usha Lee McFarling Two scientific teams announced Monday they have discovered the most compelling evidence yet from a Martian meteorite showing that life once existed on Mars. But the findings have not convinced many critics who say such claims continue to be overblown.

The evidence comes from the highly controversial Martian meteorite dubbed ALH840001. Claims made about traces of fossil life found in the 4-pound, potato-shaped meteorite in 1996 were met with skepticism and even scorn by fellow scientists.

Some of those dramatic claims -- including one that small worm-shaped objects in the rock were fossilized Martian creatures -- have been retracted. Another claim, that carbon compounds in the rock were the decayed bodies of ancient Martian organisms, has been stymied by arguments that such compounds could be created inorganically, or without life.

No one is suggesting the 4.5-billion-year-old rock is evidence of current life on Mars, now a cold, dry and apparently lifeless place. But many scientists suggest that the Mars of a few billion years ago was more hospitable: warmer, wetter and possibly a home to life. In these meteorites, the teams are studying evidence of what could be fossilized traces of life.

The strongest evidence for ancient life within the meteorite now rests with tiny magnetic crystals, called magnetite, in the space rock. The purity, shape, size and orientation of the crystals suggests they were created by a special type of bacteria that uses magnetite crystals as compasses, said Kathie Thomas-Keprta, a microscopist with Lockheed Martin who has studied the rock intensively.

"People say, 'Magentite, that's not too sexy.' But it might be as useful as dinosaur bones," said Thomas-Keprta. Thomas-Keprta's team is reporting in today's issue of the Proceedings of the National Academy of Sciences that the shape of the crystals found in the meteorite is identical to crystals created by a bacterial strain on Earth called MV-1. That bacteria lives in water, can survive without oxygen and can gain its energy from carbon dioxide.

"That fits just perfect with what we would see on Mars," said Thomas-Keprta, who said she believes the 3.9-billion-year-old crystals represent the "oldest life form ever found." Because of their configuration within the space rock, the crystals would have had to form on Mars, rather than forming on Earth after impact, scientists said.

The teams suggest that the magnetotactic bacteria lived in martian mud billions of years ago and that remnants of the bacteria were forced into harder rock by the impact of a meteorite onto the Martian surface. A subsequent impact, 13 million to 16 million years ago, then sent the rock into space for a long journey that ended on earth about 13,000 years ago when the rock landed on the Allen Hills Antarctic ice sheet, where it laid until its discovery in 1984.

Another report, by an international team led by biologist Imre Friedmann of Florida State University and NASA Ames Research Center, showed that the crystals exist in chains. The chains are surrounded by halos that appear to be remnants of bacterial membranes that once surrounded the crystals.

"Chains cannot be produced inorganically. A chain of magnets would immediately collapse into a clump because of the magnetic field. What keeps them from collapsing is the organism itself," said Friedmann. "There's no way it's not a biological scenario."

Other evidence that the magnetic crystals are biological in origin comes from earlier work by Thomas-Keprta indicating that the crystals are not touching each other, as inorganic magnets would, but were separated, possibly by a thin biological membrane.

The crystals -- so small that 1 billion would fit on the head of a pin -- are also very uniform, and in strange orientations not dictated by the forces of magnetism. This suggests that biological forces might have influenced them, said Simon Clemett, a cosmochemist at Johnson Space Center in Houston. Clemett began studying the rock in the mid-1990s while a graduate student at Stanford.

But the theory is still far from being proved, according to other scientists.

"I'm not convinced they're wrong -- but I'm not persuaded they're right," said Peter Buseck, a minerologist at Arizona State University and expert on magnetite crystals. "Not everyone shares their optimism."

Whether there was life on an ancient Mars, said Doug Ming of the Johnson Space Center, remains "an open question" that won't be answered until scientists "drill and go down deep" beneath the Martian surface and possibly return samples of Martian rock to Earth for study.



-- Lars (larsguy@yahoo.com), February 27, 2001

Answers

The scientists had no explanation for the small green 3-toed footprint on the meteorite.

-- Lars (larsguy@yahoo.com), February 27, 2001.

THIS would be cool if it could be proven true (by a consensus, I suppose; or however they do that).

I've always thought, only half-jokingly, that if we're the only ones out there, we're in pretty deep doo-doo.

[What do you suppose the qualifications would be for a "cosmochemist"? Sounds like something to do with an acid trip gone horribly wrong....... :-)]

-- (PatriciaS@lasvegas.com), February 27, 2001.


Something I have wondered about is if (when) intelligent life is discovered on another world, how will the various religions deal with it? In Christianity, for example, did Christ die for the sins of the alien too? Or maybe each planet had its own Savior (same God different Saviors). Well I think Christian apologists, Muslim apologists, Jewish, etc had better be ready.

Cosmo-chemists are very sexy.

-- Lars (larsguy@yahoo.com), February 27, 2001.


That's funny, Lars; I used to wonder about that, too, when I was younger. I suppose it's because I was "closer" at the time to my Catholic upbringing.

It would be interesting to see the reactions of the various religions to such a phenomenon, not only in the vein of "did Jesus die for their sins, too", but did God create them as well? And what would constitute an "alien sin"? It would be difficult (if not impossible) to project all our human emotions, society, etc. on alien life forms.

They'd probably sit there LTAO at us. And rightfully so.

I think you just like the sound of "cosmochemist"; it sounds sexy.

-- (PatriciaS@lasvegas.com), February 27, 2001.


Lars:

Something I have wondered about is if (when) intelligent life is discovered on another world,

Let's hold that thought until we find intelligent life on one planet. When it is located, let us hope that it isn't on the planet of the Aint's *<)))

Cheers,,,,

Z

-- Z1X4Y7 (Z1X4Y7@aol.com), February 27, 2001.



there was life on other planet's and GOD destroyed the=rebellion!!!!

-- al-d (dogs@zianet.com), February 27, 2001.

Lars:

the planet of the Aint's

Sorry that should have been the planet of the Ain'ts. All us Yale Alum-neyes learnt the same languish.

Best Wishes,,,,

Z

-- Z1X4Y7 (Z1X4Y7@aol.com), February 27, 2001.


Patricia--

I mean Cosmo-chemist, as in the magazine.

-- Lars (larsguy@yahoo.com), February 27, 2001.


When I was a kid I wanted to meet aliens from another world and went so far as to put out mental signals - "Land here!".

The past several years I've done the opposite, even purchasing an ultra-sonic Aliens Away device. It's kinda like the device one attaches to an automobile to warn deer off the road. Bought it from Art Bell.

So far it's worked perfectly. Not a single alien visitor has darkened my doorstep.

-- Rich (howe9@shentel.net), February 28, 2001.


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