Microbes on Mars

Microbes on Mars ?

If Mars had life, then there could still be microbial life even today. This has been speculated before as one source of Methane sometimes coming to atmosphere of Mars. Curiosity has observed that the methane in atmosphere from time to time rises ten times higher compared to normal level (source: Christopher R. Webster, 16.12.2014: Mars Methane Detection and Variability at Gale Crater , and Christopher R. Webster et all, Science June 2018 Background levels of methane in Mars’ atmosphere show strong seasonal variations ).

In Earth only certain types of microbes produce methane, not all. In soil of Mars Curiosity observed methane ( source: S.Djordjevic 2014: Simulating Martian conditions: Methanogen survivability during freeze-thaw cycles ). Methanogens are organisms which are anaerobic, do not require organic nutrients, and are non-photosynthetic. In the tests reported in article above four species of methanogens were tested in laboratory in conditions simulating Mars: low air pressure, higher level of radiation and large temperature variations. Two of the methanogen species survived the tests and even reproduced. Read also related article by Italian geologist and environmental engineer Pietro Cambi, March 2017: There was life on Mars and not only on Saturday night ... (the link is a google translation of original Italian language article C'era vita su Marte e non solo il Sabato sera…). Cambi presents good arguments that the observed methane on Mars comes from biological origin. The abiotic hypothesis fail to produce the observed amount of methane by several orders of magnitude.

Another microbial species proposed to survive well in Martian conditions are chemolithoautotrophs . This species exists also widely in Earth underground and inside stones, even kilometers deep underground. They use the stones and minerals as energy source. The underground microbes may form 80 percent of all biomass on Earth [118]. There are also bacteria which interact with sulfates. Bacteria which interact with sulfur may play a role with in seasonal color changes of surface of Mars [63].

Below left: Curiosity Sol 304 (14.6.2013). There is something white in stone hole. Curiosity stopped on Sol 303 to take close up images of this with Mars Hand Lens Imager (MAHLI). Right: Opportunity Sol 3392. Microscopic camera shows holes and tubes with some small objects on them. Do we see here Martian organisms based on stone and minerals eating chemolithoautotroph microbes?

You can get the Curiosity Sol-304 original image here and the Opportunity Sol-3392 image here. Below is comparison of the Sol-303 and 304 white objects in stone hole with 26 hours difference.

When you study the Sol-303 and Sol-304 pictures, you notice fine grained sand left on places where there is no more white material. You could imagine that during the sandstorms of Mars this sand is blown away from the stone holes. From Mast Camera images of Sol-305 and 306 you can see that Curiosity is still exactly in same position besides this object, but there is no close up images with MAHLI of this object in the archive.

The Sol-304 and 306 images below are from the same stonewall. Here it is possible to consider possible development of stone holes, so that on left there is start situation with the white material on the surface and later development phase is on right. On right the A-arrow is the Sol-304 stone hole object presented above.

In image below there is a larger occurrence of the white material, Curiosity Sol-158. Notice the similarity of Sol-158 objects compared to Sol-304 object.

Below is Opportunity Sol 3392 image composition.

Curiosity science-team published 6 remarkable articles in Science magazine 9.12.2013.. You can get the original articles under this link (select Reprint). One of articles is by the Curiosity principal investigator John Grotzinger, signed by 60 other scientists: A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars. The main message of these articles is that Mars has had good conditions for life. Below is few highlights of the article.

• Curiosity has analyzed the substances on the ground in Gale Crater area. There is all needed basic elements for life: water, coal, hydrogen, oxygen, sulfur, nitrogen and phosphorus.

• Gale crater has had a lake, with conditions suitable for life. The pH of water has been neutral. Water would have been drinkable.

• In the area there is a lot of clay-minerals and mudstone. The hardness of them is weak/medium.

• In chemical analysis with SAM equipment, while heating the samples, water and carbon dioxide was released among other substances. The result of analysis is that the area contains remarkable amounts of organic matter.

• The white veins and nodules (images below) contain sulfates. For the first time NASA gives as one possible explanation alternative for the veins and nodules a living thing. Here is a direct quote from the article: "A final possibility considers the potential role of microbes, if life had ever evolved on Mars. Terrestrial sediments are pervaded by microbes, which produce a variety of gases that become trapped as bubbles where lithification is early and rapid (43). However, it should be clear enough that this mechanism can only be invoked as a serious possibility after all other abiotic hypotheses have been discounted. This is not the case for our current data set and we include this only for the sake of completeness." I handle the possible reasons for the cautious statement "..we include this only for the sake of completeness" in this this web-site.

• The conditions in the area would be suitable for stone and minerals eating microbes called chemolithoautotrophs . Source: Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars by D. T. Vaniman. Direct quote: "...The possible formation of H2 gas as part of this process could be another component of habitability, providing a potential energy source for chemolithoautotrophs."

In Curiosity science team article in Science magazine 9.12.2013 it is told that this John Klein area had a layer protecting from radiation as recently as 60 to 100 million years ago. The protective layer has preserved organic materials so that Curiosity is able to find them in chemical analysis. See article: NASA Curiosity: First Mars Age Measurement and Human Exploration Help .

In many Curiosity pictures there are white veins with nodules on the ground like in Sol-192 and Sol-181 images below, at John Klein site. In Sol-181 picture dust has been brushed away. And from drilling picture of Sol-270 image (drilled in sol-182) we see that the veins seem to go deep inside ground. Read this interesting NASA News about chemical analysis result of this drilling sample: NASA Rover Finds Conditions Once Suited for Ancient Life on Mars . In drilling picture it can be seen that under the thin red surface layer there is gray clay layer. There is 2-3 percent of water (locally even 6 percent) mixed in the soil. So the soil has moisture, which you can observe also visually in the drilling hole below. Great place for microbes to live.

In high resolution picture you can see new white veins with new white nodules. And you can see old vein traces with old nodules without the white material. For the first time NASA gives as possible explanation possibility a living object for these white veins in article published in Science magazine 9.12.2013: A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars.

An excellent, freely readable, study of microbial life on Mars is by Dr. Lyall Winston Small, September 2015: On Debris Flows and Mineral Veins - Where surface life resides on Mars . Dr.Small points out in his book, chapter 4.6, that mineral veins on Earth are often populated with microbial activity.

Below is comparison of John Klein area veins. Difference is 78 days. There are visible changes. Curiosity investigated John Klein area for 3 weeks and came back to check the area after 2 months.

The white veins and nodules exist very widely in Curiosity and Opportunity pictures. There is new veins and nodules and old ones without the white material visible anymore. They exist on the ground, deeper inside ground and on the stones. In image archives there are several pictures where you can figure out that parts of stones have dropped to ground just on the place where white veins were inside the stone (e.g. in Sol-303 images). Below is 2 more images to compare for changes during 78 days.

At John Klein site Curiosity drilled first a test hole and after that the hole for getting a sample for analysis. Both in the test hole and in the final hole we see the white veins on the walls of the holes. Also in Cumberland sample hole we see the veins, but not on Windjana hole. So the John Klein and Cumberland samples both contained the white vein material, for which NASA has stated as one alternative the microbes. Analysis with SAM indicated organic materials in John Klein and Cumberland samples. John Klein test holes were drilled Sol-182. Curiosity was sent back to John Klein area in Sol-270 to check the place again. Can we see changes in John Klein hole veins during 78 days? The holes are only 1.6 centimeters wide. Having a lot of veins in 3 of the 4 sample holes, shows how widely spread the veins are in Mars. And they may be microbial. The images D and E are the same John Klein sample hole as C, but from another angle.

Below are more candidates for possible microbial communities. Curiosity has used Chemistry camera to Sol 608 and 609 objects to analyze the chemistry of them. These both are just about 50 centimeters distance from the Windjana drilling site. In last row there is underground soil as result of failed test drilling. There are changes during 11 days. Note especially the dark greenish grains or patches which have appeared in Sol 880 image (arrows B and C). Normal sand grains should be reddish in color. The opportunity Sol 3502 has also interesting hole in low right part of image. From small Sol 3949 image you can see that the color of the Sol 3502 lichens resembling objects is white.

In S-2 image seems like the white material is 'growing out' from the stone. The stone itself has nice greenish( or blue?) color as well as the sol 580 stone. Cyanobacteria ? Algae ? In Sol 580 and Sol-305 images i have embedded part of the images with auto white balanced versions, which reveals a strong blue color. The Sol-304 is close to Sol-305 object and also in the same stone wall as the Sol-304 'chemolithoautotroph' images in beginning of this web-page. The yellow color tones and formations in Sol 584 image are interesting. Curiosity science team investigated closely the Sol 1411 object, which resembles the Sol 305 S-2 object. The same stone has more of these.

An excellent, freely readable, study of possible microbial life on Mars is by Dr. Lyall Winston Small, September 2015: On Debris Flows and Mineral Veins - Where surface life resides on Mars . And see also Dr.Small's year 2012 book In search of life on Mars and his observations from Mars rover images in SmugMug . He is also the founder of Mars Rover Blog where Mars enthusiasts analyze images of Mars rovers. Check out for example discussion thread Yellowknife Bay and Mount Sharp - Extended Mission 1 . On July 2016 Dr.Small made a new web site The Cosmos, Mars and Life , where he handles daily discoveries from Mars and also philosophical aspects of the discoveries.

Sol 2160 image by Opportunity is observations presented by Dr.Small in his book In search of life on Mars [137].

There is blue objects on stone surfaces resembling lichens in this area. This area has also Blueberries. Sol 925 area veins are interesting. Sol 1090 veins look very fresh. They are dustless and on top of geological formations. In sol 1063 green fresh looking material covers old geological formations.