The rock from Mars: ALH84001

The famous rock from Mars, ALH84001, was ejected into space by an asteroid impact on Mars long ago. It traveled through space for ~16 million years, and finally landed in the Allan Hills ice field in Antarctica about 13,000 years ago where it was collected by a team of scientists in 1984. This magnified, optical view shows the unusual orange and black disk patterns which are made of carbonate, a mineral that forms at low temperature in the presence of water. The meteorite made its way into headlines worldwide in 1996 when astrobiologists announced that it might contain evidence of microscopic fossils of Martian bacteria. The veracity of this claim is still debated today! Whether true or not, this discovery launched the field of astrobiology as we know it.

Image Credit: Kathie Thomas-Keprta and Simon Clemett/ESCG at NASA Johnson Space Center, via From Earth to the Universe.

Posted: 29 April 2011
About the Author:

Alex di Giovanni has been editing The Torch since August 2006. Prior to joining the Smithsonian, she worked as a writer and editor for the National Geographic Society, Plexus Scientific, The Nature Conservancy, The National Foreign Language Center and St. Martin’s Press, among others. She has the best job in the world.