SETI Institute | 2016 May 23
[img3="Ancient layered clay-bearing bedrock (top left) and carbonate bedrock (bottom right) are exposed in the central uplift of an unnamed crater approximately 42 kilometers in diameter in eastern Hesperia Planum, Mars.Recently discovered evidence of carbonates beneath the surface of Mars points to a warmer and wetter environment in that planet’s past. The presence of liquid water could have fostered the emergence of life. ...
(Credit: MRO/HiRISE NASA/JPL-Caltech/University of Arizona)"]http://www.seti.org/sites/default/files ... _Fig_2.jpg[/img3][hr][/hr]
The fate of water on Mars has been energetically debated by scientists because the planet is currently dry and cold, in contrast to the widespread fluvial features that etch much of its surface. Scientists believe that if water did once flow on the surface of Mars, the planet’s bedrock should be full of carbonates and clays, which would be evidence that Mars once hosted habitable environments with liquid water. Researchers have struggled to find physical evidence for carbonate-rich bedrock, which may have formed when carbon dioxide in the planet’s early atmosphere was trapped in ancient surface waters. They have focused their search on Mars’ Huygens basin.
This feature is an ideal site to investigate carbonates because multiple impact craters and troughs have exposed ancient, subsurface materials where carbonates can be detected across a broad region. ...
Orbital Evidence for More Widespread Carbonate-Bearing Rocks on Mars - James J. Wray et al
- Journal of Geophysical Research 121(4):652 (Apr 2016) DOI: 10.1002/2015JE004972