This shows a possible elongated fossilized Martian cell on the surface of a clay mineral inside a Martian meteorite. Other possible fossilized microbes are partly embedded in the clay mineral. This clay mineral is now known to have formed on Mars about 700 million years ago. A NASA research team of scientists at the Johnson Space Center and at Stanford University has found evidence that strongly suggests primitive life may have existed on Mars more than 3.6 billion years ago. The shadow of the Martian moon Phobos is captured by the Mars Global Surveyor Mars Orbiter Camera.
Many people ask how scientists know the meteorite originated on Mars.
Most Martian meteorites are 1.3 billion years old or less, much younger than typical igneous meteorites from asteroids which are 4.5 billion years old. They also have higher contents of volatiles than igneous meteorites. The conclusive evidence that this meteorite originated on Mars comes from the measurement of gases trapped in its interior. The trapped gases match those that Viking measured in the Martian atmosphere. More . . .