Printer Friendly

Life on Mars: Take two.

They're at it again. The same team that 3 years ago made the controversial suggestion that a 4.5-billion-year-old Martian meteorite contains fossils of tiny bacteria has now announced finding similar fossils in two much younger rocks from Mars.

Using electron microscopy, researchers from NASA's Johnson Space Center in Houston and their colleagues identified minute spherical and rod-shaped features suggestive of fossils in the Martian meteorites Nakhla, about 1.3 billion years old, and Shergotty, about 180 million years old.

"Because we are finding evidence for fossilized organisms in meteorites with such young ages, it is conceivable that there could still be life somewhere on Mars at the present time," says study collaborator Kathie Thomas-Keptra of Lockheed Martin Corp. in Houston. Her team announced the findings in March at the annual Lunar and Planetary Science Conference in Houston.

Thomas-Keptra says the possible fossils have much in common with mineralized bacteria found in terrestrial rock known as Columbia River basalt. The spherical and rod-shaped features in the Martian samples are rare but occur in patches, a pattern "highly suggestive of biological activity," she notes. "Inorganic chemical precipitation, for example, would not likely occur in sporadic, random, colonylike patches."

John P. Bradley of MVA in Norcross, Ga., and the Georgia Institute of Technology in Atlanta says it's best to keep an open mind. However, he says that there's no compelling evidence that these features must be fossils. "The absolutely key prerequisite is to look inside these objects to see if you can see cellular structure," he says. "In the absence of that, [the scientists are] going to spin their wheels."
COPYRIGHT 1999 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1999, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:minute spherical and rod-shaped features identified on Mars
Publication:Science News
Date:May 1, 1999
Previous Article:Black holes go middle class.
Next Article:Some fats may ward off colon cancer.

Related Articles
Meteorite hints at early life on Mars.
More findings about life on the Red Planet.
Meteorite still holds inklings of life.
Postcards from the Red Planet.
Why Mars? New polls show that Mars is students' favorite planet. Why the fuss over our next-door neighbor? (Earth Science: Space Exploration *...
Exploring the Red Planet: Mars Odyssey set to begin its mission.
So, you want to go to Mars: sorry, you can't pack your toothbrush yet. But in January 2004, two NASA rovers will bring you closer than ever to our...
Blueberry hills: Utah nodules resemble some found on Mars.
Martian landscaping: spacecraft eyes evidence of a frozen sea.

Terms of use | Privacy policy | Copyright © 2020 Farlex, Inc. | Feedback | For webmasters