Free Astronomy Magazine March-April 2015

ASTROBIOLOGY ses modelling a sec- tion of a sedimentary rock outcrop, up to randomly give it many of the characteristics of terrestrial MISS fos- sils. The NASA team in charge of Curiosity’s activities openly sup- ports the latter hy- pothesis, a position which effectively re- jects all arguments put forward by Nof- fke in a detailed ar- ticle published online in Astrobiology last De- cember (and in print- ed form in January). The author herself is however duly cau- tious about her inter- pretation of those specific Martian struc- tures and is the first to admit that further studies will be need- ed in order to prove (or disprove) their bio- logical origin: “All I can say is, here’s my hypothesis and here’s all the evidence that I have, although I do think that this evidence is a lot.” “In one image, I saw something that looked very familiar. So I took a closer look, meaning I spent several weeks investigating certain images centimeter by centimeter, drawing sketches, and comparing them to data from terrestrial structures. And I’ve wor- O n the side, some exam- ples of fossil structures found in the Dresser Formation (Pil- bara, Western Australia) and their modern ana- logues. From top to bottom are shown chips, roll- ups, pockets. [Nof- fke et al. 2013] Below, another comparison be- tween Mars and Earth, taking as example struc- tures generated by the erosion of microbial mats at Carbla Point, Western Austra- lia. [NASA, Nora Noffke] ked on these for 20 years, so I knew what to look for.” “But if the Martian structures aren’t of biological origin, then the simi- larities in morphology, but also in distribu- tion patterns with regards to MISS on Earth would be an extraordinary coinci- dence.” “At this point, all I’d like to do is