Free Astronomy Magazine March-April 2015

5 MARCH-APRIL 2015 ASTROBIOLOGY W e could be facing the greatest discovery in the history of man- kind: “Identified on Mars structures seemingly compatible with the fossil remains of microbial colonies”. This sensational news began to spread last December and in a matter of weeks it was taken up by numerous sources of information, attracting the attention of both the scientific community and the general public. Everything began in August 2012, with the landing of the rover Curiosity inside the Gale Cra- ter. In December of that year, the sophisticated self-propelled labora- tory reached the Yellowknife Bay area, for sure occupied by liquid water s, the circle T he “Whale Rock”, in the Pah- rump Hills area, is a clear example of how the Martian water has shaped and eroded the surface of the red planet in its first billion years. This type of sedimentation may have been a favourable habitat for the exis- tence of large bacterial colonies. [NASA/JPL-Caltech/MSSS]