Salty water on Mars could contain dissolved oxygen, says Katherine
Kornei at EOS.org 11/2/18.It might be in Gale Crater, Curiosity’s landing site. The salty watermight be enough to house a few microbes or sponges. Rock formations andsoil indicators suggest that water once flowed on Mars. There couldstill be some underground water there. A “small probe” (Th2OR) will tryto detect sub surface ground water on Mars to a few kilometers.
Another problem for life there, however, is Mars’s thin atmosphere of 96% carbon dioxide. The good news is its low obliquity, which could meana high oxygen solubility, enough to support microbes with aerobic respiration.
NASA’s Mars 1010 mission will be focused on possibilities for microbial signatures. Oxygen in an atmosphere is one of the indicators of life on exoplanets that TESS might find–maybe. We need to remember that there was no oxygen in Earth’s atmosphere 1.87 billion years ago, when microbes were the only critters alive here. Now the level is 20%, thanks be.
Noah Planavsky of Yale University is looking at rocks that contain cerium. As little as 0.1% present suggests that life has been around, if I understand his using cerium as a proxy for oxygen levels. Cerium binds oxygen in sea water, so the contents of sedimentary rock can be indicative of the presence of oxygen in the atmosphere.
The elephant in the room appeared on 11/15/2018 in https://eos.org/articles by Katherine Kornei, writing about Chile’s Atacama Desert–the “driest place on Earth,” receiving only millimeters of rain per year. There an unusual rainfall in 2017 created “hypersaline
lagoons.” As a result, most of the microbes there died, since they had been “adapted to millions of years of dry conditions.”
Astrobiologist Armando Azua-Bustos of the Center for Astrobiology in Madrid, Spain, noticed pools of water in 2015 in the Atacama, which had essentially no rain during the past 500 years. When temporary lagoons appeared again in 2017, he and his colleagues studied the microbial life in the area. The three lagoons measured 10 to 30 centimeters deep and
were found to house only two to four species of bacteria. Hyperdry soils housed 16 different species of “bacteria, archaea, and eukaryotes.” In nature.com Scientific Reports
(https://www.nature.com/articles/S41598-018-35051-w) they reported that 70% of the species in the soil had disappeared, probably from osmoticstress. “‘They burst like balloons,’ Azua-Bustos said.” They had analyzed samples of lagoon water searching for biomarkers with microscopy, RNA gene sequences and cultivation. Now they are checking
to see if the “…ecosystems are recovering.”
The warning is clear for how we might take samples from other planets. If life can evolve is such super dry places as Atacama, all samples taken for signs of life should not be incubated in aqueous solutions, as was down with “…the Viking landers on Mars in the 1970s…”
Carolyn A. (Cary) Neeper
Author of The Archives of Varok
The View Beyond Earth (Book 1.)
The Webs of Varok (Book 2.)
Nautilus Silver Award 2013 YA
ForeWord IBPA finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest (Book 4. Released Nov.21, 2016)
Excerpts, Synopses, Reviews, On Writing, Characters and More-
Reviews of significant books- http://www.goodreads.com/Cary_Neeper
How the Hen House Turns- http://www.ladailypost.com
Complexity, Bio, Bibliography and Links- http://caryneeper.com
Astrobiology- https://astronaut.com search:Who’s Out There