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Work in progress for two new sections for: Present day Mars habitability analogue environments on Earth

So far this is just source material in the form of citations and quotes.

High Altitude Lakes in the Andes[edit source | hide | hide all]

"The Sairecabur volcano (5971 m), in the Atacama Desert, is a high-altitude extreme environment with high daily temperature variations, acidic soils, intense UV radiation, and low availability of water. Four different species of yeasts were isolated from this region using oligotrophic media, identified and characterized for their tolerance to extreme conditions. rRNA sequencing revealed high identity (>98%) to Cryptococcus friedmannii, Exophiala sp., Holtermanniella watticus, and Rhodosporidium toruloides. To our knowledge, this is the first report of these yeasts in the Atacama Desert. All isolates showed high resistance to UV-C, UV-B and environmental-UV radiation, capacity to grow at moderate saline media (0.75–2.25 mol/L NaCl) and at moderate to cold temperatures, being C. friedmannii and H. watticus able to grow in temperatures down to −6.5°C. The presence of pigments, analyzed by Raman spectroscopy, correlated with UV resistance in some cases, but there is evidence that, on the natural environment, other molecular mechanisms may be as important as pigmentation, which has implications for the search of spectroscopic biosignatures on planetary surfaces. Due to the extreme tolerances of the isolated yeasts, these organisms represent interesting eukaryotic models for astrobiological purposes."

"The Atacama Desert presents great daily temperature variations, but due to the high altitude, the temperatures are mainly colder than in lower areas, being the capacity to develop at temperatures as low as 0°C a possible advantage to such organisms. In addition, as has been already pointed out by Chin et al. (2010), the presence of chaotropic salts found on Mars may favor the survival of cold, tolerant microorganisms at lower temperatures. Recently, Fischer et al. (2014), studying the chaotropic salts NaClO4 and Ca(ClO4)2 have demonstrated that regions where salts and ice coexist in Mars might form liquid brines temporarily, which could allow microbial growth to thrive, even on the surface of that planet. Also, according to Osterloo et al. (2008), chlorides salts are globally spread on Mars. Thus, the capability of thriving at temperatures below the freezing point in chaotropic solutes (as glycerol) or in kosmotropic solutes (as NaCl) as observed by C. fredmannii and H. watticus, as well the salt tolerance of the isolates, are also important when considering these yeasts by an astrobiological perspective."

" In this work, we have isolated and characterized yeasts from a high-altitude area of the Atacama Desert, which are as resistant to UV radiation as the model organism D. radiodurans, one of the best candidates to survive in extraterrestrial conditions (Diaz and Schulze-Makuch 2006; "

"Dr. Nathalie Cabrol is a planetary geologist with NASA Ames in Southern California. She is studying the presence of ancient water on Mars, and the possibility of Martian life forms. Lake Licancabur is the closest analog to Mars on earth: cold, dry, windy, and protected by only a thin atmosphere. So Dr. Cabrol is leading a scientific expedition to Licancábur from October 16 through November 9, 2002! The scientists plan to survey the highest lake on earth, dive in its depths, catalog the bacteria and algae that live there, and look for extremophiles that can survive the harsh ultraviolet light at 19,000 feet. You can read more about the expedition at the following web site:

"Dr. Cabrol reports that there is another high lake on the Sairecabur volcano nearby. The Sairecabur lake is seasonal only. The following web page mentions the lake in the summit crater of Escalante:

"Here is a four-part article in Astrobiology Magazine about the Licancábur expedition (October 21, 2002 - November 11, 2002).

"The NASA expeditions in 2002 and 2003 repeatedly measured the summit elevation of Licancábur at 6014 meters using GPS equipment, and the lake itself at 5916 meters (98 meters below the summit). Topographical maps of the Licancabur volcano list a summit altitude of 5930 or 5916 meters, based on an older geographical survey of the area. This discrepancy is not a big deal - the heights of Mt. Everest and K2 have also been updated from the original surveys. As of December 2003 the other elevations in Chile are from the older topo maps and surveys.

"The NASA expedition also confirmed the lake size of 90 m x 70 m. Nathalie Cabrol recorded a water depth of 5.2 meters (17 feet) in one spot using a hand-held sonar device, but that may not be absolutely the deepest point. Chris Goulet found green algae and red bugs swimming in the lake in 1993: "

"Once living organisms reach water, provided that they are mobile and not immobile periphyton, they can escape deadly exposure by population the deepest waters and use the water column as an efficient UV shielding mechanism. This strategy works well in perennial lakes and could have been used in early Mars with some measure of success. As conditions deteriorated, the atmospheric pressure decreased and evaporation increased. Life in these lakes would have faced mounting difficultly to find effective shielding conditions if they remained in the water.

"Very high altitude lakes in the Andes may present curruently the best analogues to these critical conditions on Mars 3.5 Ga ago. "

High-Up: A Remote Reservoir of Microbial Extremophiles in Central Andean Wetlands The High-Lakes Project Changing Planetary Environments and the Fingerprints of Life - analogues of early Mars transitioning to present

Lanzarote, Canary Islands[edit source | hide]

Lanzarote Canary islands Mars analogue

Planetary and astrobiological significance of Canary Islands (just abstract doesn't say much)

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