Based on a study of magnetization within rock, aresearchers from the California Institute of Technology (Caltech) believe that microbes could have survived a trip from Mars to Earth inside a meteorite. Martian meteorities are chunks of Mars that were blown into space when an asteroid hit the Red Planet. They floated in space for a time, then landed on Earth. Team co-leader Benjamin Weiss estimates that roughly a billion tons of Mars rocks have been transferred to Earth in this way. And experiments have shown that bacteria can survive for years in outer space in a dormant state. In 1996, a group of NASA scientists ignited controversy when they announced that they had found fossilized microorganisms in Martian meteorite ALH84001. Many scientists doubted that life forms could have survived the intense heat of the initial impact or the entry into Earth's atmosphere. When molten rock cools, it generally magnetizes in the direction of the planet's magnetic field. However the Caltech team found that magnetization within ALH84001 showed no pattern of alignment, suggesting that the core of the meteorite never became hot enough to melt. Understanding the natural processes by which life can migrate from one world to another is a major objective of astrobiology.
Nov 26, 2002 | SCIENCE, MISSIONS
Surviving the Final Frontier
(Astrobiology Magazine) - Can microbes travel between planets aboard meteorites?
Dec 05, 2001 | SCIENCE, TECHNOLOGIES
Debate Rages on over Evidence of Mars Life in Meteorite
(Spaceflight Now) - Scientists argue the significance of magnetic crystals found inside Martian meteorite ALH 84001.
Nov 02, 2001 | SCIENCE, MISSIONS
Why Microbes Matter
(NASA Astrobiology Institute) - A key question facing astrobiology is whether life has arisen independently elsewhere in our universe.
Oct 26, 2001 | SCIENCE
The Three Domains of Life
(NASA Astrobiology Institute) - For many years, scientists divided life into five kingdoms: animals, plants, fungi, protists, and bacteria. But in recent years the discovery of a group of microbes called archaea has radically altered this view.
Apr 30, 2001 | SCIENCE
Does the Famous Martian Meteorite Really Point to Life?
(NASA/Space.com) - Debate continues over whether Martian meteorite ALH84001 contains evidence of ancient life on Mars.
Oct 30, 2000 | SCIENCE
The new case for panspermia
(Space.com) - The theory that microscopic life can spread from planet to planet is hotly contested. This feature article reviews the history of that debate.
Oct 18, 2000 | SCIENCE
Bacteria brought back to life after 250 million years
(BBC) - Microbes dormant for 250 million years have been revived. The findings may have implications for the search for life on Mars and for the origin of life on Earth.
Jul 26, 2000 | SCIENCE, MISSIONS
Yellowstone microbes ride on NASA rocket
(CNN) - The flight is testing whether meteorites could have spread life from one planet to another.
Jun 05, 2000 | SCIENCE
New Martian meteorites found
(space.com) - Researchers have identified five more rocks from Mars.
May 03, 2000 | SCIENCE, EDUCATION
Astronauts hunt microbes and meteorites at the South Pole
(Science@NASA) - Astrobiologists and astronauts -- including Jim Lovell of Apollo 13 -- traveled to Antarctica in January to study microbial life there. Their findings will shed light on whether life may exist on frozen bodies such as Mars and Europa.
Mar 01, 2000 | SCIENCE
Sulfur in meteorites offers no evidence of Mars life
(SpaceViews) - Scientists claim that that sulfur concentrations found in Martian meteorites are the result of atmospheric processes and not of life on Mars. Sulfur concentrations may not be an effective biomarker.
Jan 13, 2000 | SCIENCE
Panspermia theoretically possible, say scientists
(Yahoo!/AP) - A team of scientists has concluded that single-celled organisms from Mars could theoretically have seeded the Earth with life, or vice versa.
Dec 30, 1999 | SCIENCE, MISSIONS
Experiment tests whether microbes can travel between planets
(BBC) - Some scientists believe that single-celled life could survive within meteorites and spread from planet to planet. An experiment aboard a space capsule will test this hypothesis.
Dec 14, 1999 | SCIENCE, MISSIONS, TECHNOLOGIES
Radiation-resistant microbe could play major role in Martian exploration
(Science@NASA) - The microbe can help scientists determine the best locations to seek life on Mars. Later, it may help
keep astronauts healthy. Finally, it may reshape Mars for colonists.
Nov 08, 1999 | SCIENCE
Asteroid may have brought Martian life to Earth
(space.com) - Recent scientific findings suggest that our ancestors -- single-celled organisms -- may be Martian.
Oct 04, 1999 | SCIENCE
Hardy Microbes appear able to survive in space
(Washington Post) - NASA astrobiologist Rocco Mancinelli's findings bolster the hypothesis that microbial life may have evovled elsewhere and spread to Earth, or vice versa. His research also underscores the need for planetary protection from exterrestrial organisms in sample-return missions.
