Is There Life on Mars? Ask a Magnet.  Is There Life on Mars? Ask
a Magnet.  A transmission electron microscope (TEM) image of
magnetite crystals from the Allan Hills meteorite ALH84001.
Between three and four billion years ago, Mars was a lot like
Earth. Both planets are believed to have had surface water.
Those similarities make it a prime candidate for
extraterrestrial life. “The assumption is that if bacterial life
emerged on Earth at that time, then why not on Mars?” says Soon
Sam Kim, principal member of technical staff at NASA’s Jet
Propulsion Laboratory.  Mars may also have had a magnetic field
much like the one on Earth. Kim believes that the presence of an
ancient martian magnetic field could be the key to tracing signs
of ancient bacterial life. He has developed methods to detect
two forms of the mineral magnetite (Fe3O4) that could act as
mineral signatures of bacterial life. One is produced by Earth
bacteria to assist with spatial orientation. The other is a
respiration byproduct generated by bac