Lichens, cyanobacteria and molds growing in humidity of simulated Martian atmosphere: Difference between revisions

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Line 1: [[Image:Martian conditions in miniature (7494313830) (2).jpg\|thumb\|Martian conditions in miniature - In the Mars simulation chamber, DLR researchers recreated the atmospheric composition and pressure, the planet's surface, the temperature cycles and the solar radiation incident on the surface. The activity of polar and alpine lichen was investigated under these conditions.]] A series of experiments by DLR (German aerospace company) in Mars simulation chambers and on the ISS show that some Earth life (Lichens and strains of chrooccocidiopsis, a green algae) can survive Mars surface conditions and photosynthesize and metabolize, slowly, in absence of any water at all. They could make use of the humidity of the Mars atmosphere.<ref name="dlrMarsStudy">[http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-3409/ Surviving the conditions on Mars] DLR, 26 April 2012</ref><ref name="sciencedirect.com">{{cite journal\|url = http://www.sciencedirect.com/science/article/pii/S1754504812000098 \| doi=10.1016/j.funeco.2012.01.008 \| volume=5 \| issue=4 \| title=Lichens as survivors in space and on Mars \| year=2012 \| journal=Fungal Ecology \| pages=472–479 \| last1 = de Vera \| first1 = Jean-Pierre}}</ref><ref name="norlx51.nordita.org">R. de la Torre Noetzel, F.J. Sanchez Inigo, E. Rabbow, G. Horneck, J. P. de Vera, L.G. Sancho [http://norlx51.nordita.org/~brandenb/astrobiology/EANA2012/single_abstracts/Delatorre.pdf Survival of lichens to simulated Mars conditions] {{webarchive\|url=https://web.archive.org/web/20130603191033/http://norlx51.nordita.org/~brandenb/astrobiology/EANA2012/single_abstracts/Delatorre.pdf \|date=2013-06-03 }}</ref><ref name="Issue 1 2012, Pages 102">{{cite journal\|url = http://www.sciencedirect.com/science/article/pii/S0032063312002425 \| doi=10.1016/j.pss.2012.08.005 \| bibcode=2012P&SS...72..102S \| volume=72 \| issue=1 \| title=The resistance of the lichen Circinaria gyrosa (nom. provis.) towards simulated Mars conditions—a model test for the survival capacity of an eukaryotic extremophile \| year=2012 \| journal=Planetary and Space Science \| pages=102–110 \| last1 = Sánchez \| first1 = F.J.}}</ref><ref name="BilliViaggiu2011">{{cite journal\|url=https://scholar.google.com/scholar_url?url=http://www.researchgate.net/profile/Charles_Cockell/publication/49810974_Damage_escape_and_repair_in_dried_Chroococcidiopsis_spp._from_hot_and_cold_deserts_exposed_to_simulated_space_and_martian_conditions/links/0c960530543245cde9000000.pdf&hl=en&sa=T&oi=gsb-gga&ct=res&cd=1&ei=M2AqVeLzG-fq0AG5xYGACA&scisig=AAGBfm1aHrkKehQaYpPYGQ9mjRxVTxPS0Q\|last1=Billi\|first1=Daniela\|last2=Viaggiu\|first2=Emanuela\|last3=Cockell\|first3=Charles S.\|last4=Rabbow\|first4=Elke\|last5=Horneck\|first5=Gerda\|last6=Onofri\|first6=Silvano\|title=Damage Escape and Repair in DriedChroococcidiopsisspp. from Hot and Cold Deserts Exposed to Simulated Space and Martian Conditions\|journal=Astrobiology\|volume=11\|issue=1\|year=2011\|pages=65–73\|issn=1531-1074\|doi=10.1089/ast.2009.0430\|pmid=21294638\|bibcode=2011AsBio..11...65B}}</ref> Though the absolute humidity is low, the relative humidity at night reaches 100% because of the large day / night swings in atmospheric pressure and temperature. This is relevant to the search for native life on Mars and also to planetary protection, the need to protect Mars from Earth life if we wish to study native life in the habitats in its original state. ==Humidity observations of the Mars atmosphere by Curiosity and Viking== The humidity variations on Mars are mainly due to variations of temperature of the air, with colder air having a higher relative humidity for the same water content. The volume mixing ration of water vapour varies up to around 70 ppm, and is anti-correlated with the humidity, with the highest humidity at times of least VMR. [[Curiosity humidity measurements.gif\|Upper chart shows the humidity, lower chart shows the volume mixing ratio in parts per million, both measurements taken at the same time, height 1.6 meters above the ground]] [[Curiosity temperature measurements.gif\|Upper chart shows the average temperature, lower chart shows the range, the warm orange and red colours are Curiosity annual readings, the blue and green dcolours are for the Viking landers and the gray colours are for the Phoenix lander]] Curiosity has measured relative humidity readings of up to 70% in winter, measured at a height of 1.6 meters above ground level (see Sect 14<ref>[https://link.springer.com/article/10.1007/s11214-017-0360-x#Sec14 Sec 14]</ref>. This is in winter with a temperature range of around 50 C and mean temperature around -63 C, so lowest temperature around -88 C (see their figure 5<ref>[https://link.springer.com/article/10.1007/s11214-017-0360-x#Fig5 Fig5]</ref>), and the highest humidity is normally reached between 04:00 and 06:00 LMST. The lowest humidity readings are between 10:00 and 18:000 LMST, when they are typically less than 5% Curiosity hasn't directly observed the frosts that Viking observed at somewhat higher latitudes. But there is indirect evidence that frosts may form at times. ==Lichens relying on 75% night time humidity==