Fallen in Morocco in 2011, the Tissint meteorite has since then been thoroughly studied by scientists. A new study, published 1st December 2014 in Meteoritics and Planetary Sciences, shows that the meteorite contains organic carbon of biogenic origin, and that this carbon infiltrated the Tissint rock on Mars, before an asteroid shock sent it towards the Earth. The voice of Hillary Sanctuary (EPFL) explains what happend in this short cartoon.
See related interview of Philippe Gillet, form EPFL’s Earth and Planetary Science Laboratory: http://youtu.be/GdJ2Uzs_LOo