Revision as of 20:56, 2 February 2024 edit JackTheSecond (talk \| contribs) Extended confirmed users 1,559 edits The (most) associated scientific field of Astrobiology is now linked to in the header, and the specific examples of mars have been separated from the more generalised writings. ← Previous edit		Revision as of 20:58, 2 February 2024 edit undo JackTheSecond (talk \| contribs) Extended confirmed users 1,559 edits a perhaps more controversial deletion of a section on life on Mars that was way too specific, separated for easy reversal... Next edit →
Line 58: No single compound will prove life once existed. Rather, it will be distinctive patterns present in any organic compounds showing a process of selection.<ref name="PhysOrg Cousins 2018">{{cite news \|url=https://phys.org/news/2018-01-rover-life-mars-proveit.html \|title=Rover could discover life on Mars – here's what it would take to prove it \|first=Claire \|last=Cousins \|work=PhysOrg \|date=5 January 2018}}</ref> For example, [[membrane lipid]]s left behind by degraded cells will be concentrated, have a limited size range, and comprise an even number of carbons. Similarly, life only uses left-handed amino acids.<ref name="PhysOrg Cousins 2018" /> Biosignatures need not be chemical, however, and can also be suggested by a distinctive [[magnetic]] biosignature.<ref name="Wall-20111213">{{cite news\|url=https://www.space.com/13911-mars-life-search-magnetic-signatures.html\|title=Mars Life Hunt Could Look for Magnetic Clues \|last=Wall\|first=Mike \|date=13 December 2011\|work=[[Space.com]]\|access-date=2011-12-15}}</ref> On [[Mars]], surface oxidants and UV radiation will have altered or destroyed organic molecules at or near the surface.<ref name="Biosignatures 2011" /> One issue that may add ambiguity in such a search is the fact that, throughout Martian history, abiogenic organic-rich [[Chondrite\|chondritic meteorite]]s have undoubtedly rained upon the Martian surface. At the same time, strong [[Oxidizing agent\|oxidants]] in [[Martian soil]] along with exposure to [[ionizing radiation]] might alter or destroy molecular signatures from meteorites or organisms.<ref name="Biosignatures 2011" /> An alternative approach would be to seek concentrations of buried crystalline minerals, such as [[clay]]s and [[evaporite]]s, which may protect organic matter from the destructive effects of [[ionizing radiation]] and strong oxidants.<ref name="Biosignatures 2011" /> The search for Martian biosignatures has become more promising due to the discovery that surface and near-surface aqueous environments existed on Mars at the same time when biological organic matter was being preserved in ancient aqueous sediments on Earth.<ref name="Biosignatures 2011" /> [[File:Biomarkers (petroleum).png\|thumb\|upright\|Structures of prime examples of biomarkers (petroleum), from top to bottom: Pristane, Triterpane, Sterane, Phytane and Porphyrin]]

Biosignature: Difference between revisions