Page "Martian meteorite" Paragraph 14

The famous specimen Allan Hills 84001 has a different rock type than other martian meteorites: it is an orthopyroxenite ( an igneous rock dominantly composed of orthopyroxene ).

For this reason it is classified within its own group, the " OPX martian meteorites ".

This meteorite received much attention after an electron microscope revealed structures that were considered to be the fossilized remains of bacteria-like lifeforms.

, scientific consensus was that the microfossils were not indicative of Martian life, but of contamination by earthly biofilms.

However, in 2009, new analyses ruled out earthly and non-biological origins, presenting strong evidence of life on Mars.

ALH 84001 is as old as the basaltic and intermediate shergottite groups — i. e., 4. 1 billion years old.