Green microbes on the red planet? NASA find: Possible fossil on meteorite cannot affect space probes for years.


LIFE ON MARS was first suggested in 1877 by the Italian astronomer Giovanni Schiaparelli. He described straight lines on the surface of the red planet as "canali," by which he meant channels, which Americans translated as canals.

His breakthrough was elucidated in 1908 by the American astronomer Percival Lowell. He mapped more than 400 canals, intersecting at dark spots he called oases, hypothesizing they -- were dug by intelligent beings to convey water from polar ice caps to deserts.

These men were not kooks but scientists on the cutting edge of theory and knowledge. Later observations, notably Mariner 4 in 1965 and two Viking landers in 1976, failed to replicate their findings, which have been consigned to the dustbin of historical curiosity.

The last time NASA looked for extra-terrestrial life (1984), it did so in Antarctica, collecting meteorites. Work on one of them was explained at a press conference Wednesday and comes out in Science next week. It is modest compared to the creative leaps of Schiaparelli and Lowell: not large, intelligent, contemporary creatures, but incredibly small micro-organisms billions of years ago. If they existed, they might well have been green.

Investigators whom NASA had examine one rock came up with && four observations, any one of which might be explained nonbiologically, that taken together looked like fossils of life. The most suggestive was a worm-like shape not one-hundredth the size of an earthling bacterium. This was inside rock they believe was formed 4.5 billion years ago, knocked loose from Mars 16 million years ago and dropped to earth 13,000 years ago.

More specimens must be examined by more scientists. This is being arranged. An expert on early Earth organisms wants the electron microscope to show him fossilized cell membranes before he believes. Lest anyone suspect this is hype to promote the NASA budget, NASA has a Mars program in place. Two robots going there later this year will not look for fossil microbes. For the 1998 mission to do so would cost extra. The first attempt to bring back a soil sample -- the logical way to go about it -- is scheduled for 2005. If that is brought forward, current interest will do it.

So despite President Clinton's promise to put Vice President Gore right on it, this newest suggestion of life on Mars will take years to prove or disprove. Evidence of life anywhere outside Earth is worth seeking.

Pub Date: 8/09/96

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