Possible present day habitats for life on Mars (Including potential Mars special regions): Difference between revisions

* '''''Lack of nitrogen'''''. All life on Earth requires nitrogen. Also there are theoretical reasons for expecting alien organic life to use nitrogen, as the weaker nitrogen based amide bonds are essential for the processes by which DNA is replicated. Mars, compared with Earth, has little nitrogen, either in the air or in the soil. Levels of nitrogen in the air are low, possibly too low for nitrogen fixation to be possible. But they can form in Martian conditions by non biological processes - either brought to Mars by meteorites (some carbonaceous chondrites are rich in nitrogen<ref>{{cite web|title=Meteorite with abundant nitrogen for life on Earth?|url=http://www.nhm.ac.uk/about-us/news/2011/march/meteorite-with-abundant-nitrogen-for-life-on-earth95139.html|website=Natural History Museum, London|date=March 4, 2011}}</ref>), or comets, or formed by lightning, or through atmospheric processes, or there may be ancient nitrate deposits from early Mars, amongst various possible sources.<ref>"Nitrogen is continuously dry-deposited from the atmosphere of Mars even today mainly as pernitric acid. During the Amazonian, 4.3 × 1018 g NO4 could have been deposited across the martian surface if all of the nitrate is formed through atmospheric photochemistry and persists without decomposition or any further reactions. This corresponds to a concentration of 0.3 wt.% N if it is mixed uniformly to a depth of 2 m. This prediction can be confirmed or disproved by future in situ measurements."</ref>

 

 

Schuerger also mentions: