An international team of researchers say they’ve found evidence of biological activity inside a meteorite that fell to Earth from Mars three years ago–in other words, possible evidence that there was once life on the red planet.
The meteorite in question is the “Tissint” specimen, which fell on the Moroccan desert on July 18, 2011.
As a team of researchers report in a new paper, chemical, microscopic, and isotope analyses show traces of organic carbon within tiny fissures in the space rock, and that the carbon had to have been deposited before the rock left Mars.
Other scientists say that the meteorite could have been contaminated with carbon from terrestrial sources, even if the carbon did originally come from Mars.
Scientists also point out that a biological origin is not the only possible explanation for the carbon found in the meteorite. Other possibilities include volcanic and/or hydrothermal activity on Mars which could permeate Tissint with carbon-bearing fluids.
The study was published online in the journal Meteoritics and Planetary Science on November 26, 2014.