Science

Publications by Science Groups

In 45th Lunar and Planetary Science Conference (LPSC) meeting 17-21.3.2014 in Texas planetary scientists, geologists and astronomers present their latest findings. The 45th LPSC meeting was heavily Mars related. There were over 300 publications concerning Mars. The Curiosity and Opportunity science teams present their latest results. Also science teams which have tested Earth microbes in conditions simulating planet Mars, present their results. See this agenda with links to all the abstracts .

The 46th Lunar and Planetary Science Conference was in Texas March 16–20, 2015. See abstracts from sessions 253: Exobiology: Prebiotic chemistry to extremophile biology .

The 47th Lunar and Planetary Science Conference was in Texas March 21–25, 2016. See abstracts from sessions 451: (Is there) Life On Mars? Martian exobiology tools, analogs, and environments , Exobiology session 702 and Exobiology session 603 .

And see abstracts of conference Mars Extant Life: What’s Next? . It was kept in National Cave and Karst Research Institute, Carlsbad, New Mexico, January 29–February 1, 2019.

Below are short descriptions and also direct quotes of the abstracts of some of the publications in these meetings.

Perchlorate reducing bacteria and the biological potential of Gale crater subsurface

From 47th LPSC meeting: K. F. Bywaters and R. C. Quinn, 2016: Perchlorate reducing bacteria: Evaluating the potential for growth utilizing nutrient sources identified on Mars. . Direct quote: Our results show that perchlorate-reducing bacteria, which may provide a good analogy for potential life on Mars, are capable of utilizing the nutrients available in martian surface materials.

Related excellent article was published in March 2016: Joop M. Houtkooper, Dirk Schulze-Makuch: The Possible Role of Perchlorates for Martian Life . The article presents a biochemical model for life on Mars in current conditions of Mars. With the model the atmospheric moisture provides enough liquid water for current surface life down to minus 70 degrees Celsius temperatures, and with sufficient level of water activity.It is good to read the whole article, but here are few direct quotes, about the basic ideas:

An interesting property perchlorate salts share with hydrogen peroxide is their effectiveness as anti-freeze. Whereas the eutectic for H2O-H2O2 freezes at -56 C, the water-magnesium perchlorate eutectic is as low as -70 C.

Why would organisms evolve to include hydrogen peroxide in their intracellular fluid? The physical and chemical properties of H2O2-H2O mixtures would be beneficial for life to cope with a harsh Martian near-surface environment. Any organisms on Mars would have been subject to evolutionary pressures, as the Martian surface became colder, dryer, and subject to higher radiation levels, to develop an adaptation to H2O2, similar to how life on Earth adapted to high concentration of free molecular oxygen about 2.5 billion year ago.

Ambient conditions on Mars are often deemed adverse to the existence of life. Mars is considered to be too cold and too dry, the soil too oxidizing, the atmosphere too thin, the solar radiation containing too much UV and there is much hard radiation from solar and cosmic origin because of the lack of a magnetosphere. However, some Earth organisms show a remarkable resistance to UV and to various types of irradiation, and adaptations to oxidative stresses and irradiation involve many of the same resistance responses in microorganisms.

Mars Odyssey data indicates water on equator areas of Mars. See articles: August 2017: Mars Probe Data Shows The Red Planet Is Hiding Water Where There Shouldn't Be Any and Icarus 2017-07-028, Jack T.Wilson Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data. Consider following possibility: Martian life may have adopted hydrogen peroxide as intra-cellular fluid, which works as anti-freeze. So Martian microbial life and fungi could bind liquid water at equatorial areas and that would be visible in Mars odyssey data.

B. J. Rodriguez-Colon and E. G. Rivera-Valentín, 2016: Investigating the biological potential of Gale crater’s subsurface.. Direct quote: Our definitions for Special and Uncertain Regions may change with new biological discoveries. Indeed, there exists strong evidence for certain metabolic processes below 255 K, but propagation by DNA replication has not yet been documented. Life as we currently know it may not persist at Gale crater due to the low temperature conditions, but our simulations suggest that liquid water, via deliquescence, with tolerable water activity is possible. This opens new possibilities for martian life.

Z.R. Harrold, E.M. Hausrath, C.L. Bartlett, A.H. Garcia, O. Tschauner, 2016: Bioavailability of mineral-bound iron to a Snow Algae community and implications for life in extreme environments . Direct quote: Laboratory results show cultures of C. brevispina and the accompanying bacterial consortia are capable of obtaining iron from nontronite. Observations from the field further suggest that iron-bearing minerals are an important source of micronutrients for snow algae-bacterial communities. Future work will probe the mechanisms of iron uptake and role of bacteria-algae interactions.

H. Yano, A. Yamagishi, H. Hashimoto, 2016: The first year operation and initial sample analysis and curation preparation of Tanpopo, the Japanese astrobiology experiment onboard the ISS-JEM-EF . There is a Japanese astrobiology experiment going on onboard International Space Station. Particles from interstellar space are collected to aero-gel on device named Tanpopo. Later particles will be analysed to test the panspermia theory: Will microbes be found in the aero-gel?

See also related 46th LPSC 2015 article: Wright S. P: Microbial Diversity Analyses of Terrestrial Shocked Basalt and Shocked Basaltic Soil: Implications for Panspermia and Future Exobiology Measurements .

Rock Varnish - Manganese coated rocks

From 45th LPSC meeting: N.L.Lanza 2014, Manganese trends with depth on rock surfaces in Gale crater, Mars . Direct quote: Because of the close association between Mn minerals and microbial activity on Earth, Mn-oxides have been suggested as a potential biosignatures for Mars missions [5, 13-14], although Mn-rich coatings may also form abiotically [15-17].

Astrobiologist Barry E.DiGregorio observed from Mars images of Viking landers that many Martian rocks have a dark tone coating similar seen in rocks on Earth. The dark coating in Earth rocks is called rock varnish. In his studies Barry was able to show that this manganese rich coating in Earth rocks is created by micro-organisms which have died on the surface of the rock. See news article about this: Rock varnish may hold clues to life on Mars . And see Barrys original year 2001 publication: B.E.DiGregorio 2001, Rock Varnish As A Habitat For Extant Life On Mars .

Below left is year 2006 image by Spirit Mars-rover with dark toned rocks possibly covered by rock varnish. On the right is Caribou target which Curiosity investigated.

Curiosity has investigated the rock surfaces on Martian rocks. The results seem to confirm Barry's interpretation that dark toned rocks on Mars are covered by manganese rich coating. And as one option is given that they are produced by microbes, as Barry suggests. Note that this Curiosity team Manganese trends article refers, ref [14], to Barrys publication linked above. See also news 21.3.2014: Bare Earth Elements: Mars rocks wear manganese coats. And read David H. Krinsley, Barry DiGregorio, Ronald I. Dorn, Josh Razink & Robert Fisher, March 2017: Mn-Fe-Enhancing Budding Bacteria in Century-Old Rock Varnish, Erie Barge Canal, New York .

Methanogen microbes in simulated Martian environment

R.L.Mickol and T.A.Kral 2014: Approaching Martian conditions: Methanogen survival at low pressure . Direct quote: Methanogens are ideal organisms for life on Mars because they are anaerobic, do not require organic nutrients, and are non-photosynthetic (they can exist in sub-surface environments). Four separate strains of methanogen (Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, Methanococcus maripaludis) were tested for their ability to survive prolonged periods of time under low pressure conditions. These four species were chosen as representives of the Archaea domain. .. Generally, the exposure to low pressure did not hinder the growth (in terms of methane production) of any of the four methanogen strains.

S.Djordjevic 2014: Simulating Martian conditions: Methanogen survivability during freeze-thaw cycles . Direct quote: Methanogens are obligate anaerobes that use molecular hydrogen as an energy source and carbon dioxide as a carbon source to produce methane. They are classified as Archaea and are found in many extreme environments, including hydrothermal vents, volcanoes, and also the human microflora. The current Martian atmosphere is low in pressure, very dry (hyper-arid), and high in radiation, and thus the surface is not suitable for life. However, the subsurface contains permafrost, liquid water [1], and trace amounts of methane [2, 3]. Thus, it is proposed that these Archaea are able to persist in Martian conditions. (End of quote)

The Methanothermobacter wolfeii and Methanobacterium formicicum survived the tests and had even increase in growth. This article also presents temperature measurements by Curiosity during 500 days. Usually the night temperature was around -80 C. But in two cases around Sol 190 and 210 the night temperature was only -5 C. Note: The old official NASA view of dry and hyper arid Mars was completely changed 28.9.2015 [132,133]. Now new NASA view is that it is wet. There is liquid water in soil and moisture in the air.

See also 46th LPSC 2015 article: Sinha N., Kral T. A: Growth of Methanogens on Different Mars Regolith Analogues and Stable Carbon Isotope Fractionation During Methanogenesis.

Very interesting test was done by Dr. Vladimir S. Cheptsov and his group in Lomonosov Moscow State University: 100 kGy gamma-affected microbial communities within the ancient Arctic permafrost under simulated Martian conditions. See also news, Universe Today, Matt Williams , November 2017 : Life on Mars can Survive for Millions of Years Even Right Near the Surface. In the simulated Martian conditions tested microbes shoved good resistance to the high radiation levels of Martian surface.

Lichens in simulated Martian environment

J.Jänchen 2014: Impact of UVC exposure on the water retention of the Lichen Buellia Frigida . Direct quote: New results on extremophiles and observations of Mars missions regarding the detailed mineralogy, the occurrence of water in the equatorial region of Mars [1-3], new announcements of MSL findings and their implications for the surface conditions at Gale crater [4, 5] as well as measurements of the Mars surface radiation environment [6] fuel the debate about possible developments of life on Mars. Based on previous studies [7-8] we examined water vapor interaction and water-bearing properties of B. frigida before and after UVC irradiation. The measurements have been partially conducted after simulation of environmental conditions which are supposed to be Mars-like. Lichens are symbiotic organisms that are able to colonize a broad range of extreme habitats and, therefore, represent useful model systems in astrobiological research.... The UVC-treatment improves the ability of physisorption of water by creating extra sorption sites in the mycobiont. The study has to be continued for getting more knowledge into this interesting outcome. (End of quote)

Lichens are symbiotic organisms consisting of fungi combined with algae or cyanobacteria. The Lichen Buellia Frigida lives in rock surfaces in Antarctica. There is close to 20000 species of lichens on Earth.

See also article by Chelsea Gohd, February 12 2017: NASA Discovers an Organism That Can Survive 16 Months in Outer Space . Quote: "Scientists aboard the International Space Station (ISS) recently ran an experiment where they let algae loose into the vacuum of space for a full 16 months. And, surprisingly enough, the simple plants survived the harrowing journey. Despite extreme temperature variations, UV radiation, cosmic radiation, and incredible length of time, the algae were brought back aboard still alive." This means that Algae type life would easily survive in Mars.

Biosignatures on Mars

Very good and comprehensive article about this area is Biosignatures on Mars: What, Where, and How? Implications for the Search for Martian Life by PhD. Frances Westall et all, Astrobiology Vol.15. CNRS-OSUC-Centre de Biophysique Moleculaire, Orleans, France.

And read also A.J.Williams 2014: Biogenic iron mineralization at Iron mountain, CA, with implications for detection with the Mars Curiosity rover. Direct quote: Microbe-mineral interactions and biosignature preservation in oxidized sulfidic ore bodies (gossans) are prime candidates for astrobiological study. Such oxidized iron systems have been proposed as analogs for some Martian environments [1]. Recent studies identified microbial fossils preserved as mineral-coated filaments [2,3,4,5,6,7,8,9]. This study documents microbially-mediated mineral biosignatures in hydrous ferric oxide (HFO) and ferric oxyhydroxysulfates (FOHS) in three environments at Iron Mountain, CA. ..... The characterization of mineral filaments as biosignatures provides insight into mineral biosignatures detectable by MSL. Individual filaments are below MAHLI resolution, but sinuous filaments forming mat-like textures are resolvable. With a suite of analyses acquired by the MSL instruments to define the geochemical and mineral environment, those features could be identified on Mars as similar to these filaments on Earth, and potentially biogenic. These features could be preserved in a crystalline hematitebearing ridge on Mt. Sharp, which is on MSL’s expected path [14].

Organic compounds and Phosphate

A.Buch 2014: Impact of the sample preparation on the organic compounds detected on mars at JK and CB. Direct quote: ... Several peaks have been identified by GCMS analysis of JK and CB as part of SAM background, some of them below the nmol level. Identification of these peaks reveal the presence of several aromatic, chlorinated hydrocarbons (Table 1) and silylated compounds such as water. The most interesting of these compounds are listed in Table 1. The question of the endogenous or exogenous origins of these compounds has to be asked. (End of quote.)

Endogenous substances are those that originate from within an organism, tissue, or cell. JK = John Klein drilling site, CB = Cumberland drilling site. See also Universe Today, Tim Reyes on December 17, 2014: NASA’s Curiosity Rover detects Methane, Organics on Mars .

S.M.Som 2014: Reactive transport modeling of Phosphate mineral dissolution in high-P Martian rock .Direct quote: Phosphate is among the nutrients considered critical for all known life [1-4]. The ion is a component in ATP, DNA, RNA, phospholipid cell membranes and required in numerous fundamental biochemical reactions [5]. Phosphorus, either as phosphate or a more reduced species such as phosphite, is also considered crucial in pre-biotic reactions that may have led to the origin of life on Earth [5-7]. A determining factor for the potential of Mars to develop and maintain life may therefore be the availability of phosphorus. ....Thus, in otherwise habitable environments on Mars, phosphate availability for potential prebiotic and biotic reactions should be comparatively higher than for Earth, a positive implication for the potential of past or present martian life.

According to this article the phosphorous availability of Mars is 5-10 times higher compared to Earth.

Special regions on Mars

D.W.Beaty and J.D.Rummel 2014: Introduction to an updated analysis of planetary protection “Special regions” on Mars. This article concerns UN Space Treaty of 1967 and the International Council for Science’s Committee on Space Research (COSPAR) Planetary Protection Policy . Meaning is to avoid harmful biological contamination between planets. There can be negative consequences of transferring life from one planet to another. There can be unknown consequences from the contact between two life forms. And when studying a new form of life, we must have thoughtfulness and caution. The “special regions” concept is defined in the COSPAR Planetary Protection Policy for Mars. These are regions “within which terrestrial organisms are likely to replicate” as well as “any region which is interpreted to have a high potential for the existence of extant martian life.” The reasons for updating the UN Space Treaty and COSPAR Planetary Protection Policy are recent findings in Mars and laboratory tests performed in Earth.

Concepts of Life in The Contexts of Mars

Another interesting meeting was The Eighth International Conference on Mars, July 2014 Pasadena California . A nice summary of meeting is by Valerie Fox, 8th Mars Report: Martian habitability. Check the Abstacts of session Biosignatures, Habitability, and Preservation and Rover-Scale Geology and Organics . Especially can be highlighted articles: D.J. Des Marais 2014: Concepts Of Life In The Contexts Of Mars. Here is direct quote from this article: Finally, evidence of ancient life should be sought in those environments that have been determined to exhibit a high combined potential for prior habitability and preservation of biosignatures. A biosignature is a substance, structure of pattern that requires a biological origin. Potential biosignatures could be indicated by the following efforts [9]: “....(2) Seek evidence of possibly biogenic physical structures, from microscopic (micronscale) to macroscopic (meter-scale), combining morphological, mineralogical, and chemical information where possible, ...".

Note especially that the point (2) can be re-written in English so that we are allowed to try to find in rover images possible fossils of ancient life of Mars. Biogenic structure is a structure produced by life process.

Dissolution cavities in stones

Barry E.DiGregorio made a groundbreaking study about dissolution cavities in Martian stones: Dissolution cavities in Upper Ordovician sandstones from Lake Ontario: Analogs to vesiculated rocks on Mars? , Proc. SPIE 4859, Instruments, Methods, and Missions for Astrobiology V, (26 February 2003). Dissolution cavities means here the following: An organism dies and gets buried in soil. During time it gets fossilized. Later acidic water can wear out the fossilized organism leaving only the hole left to the stone, a kind of negative fossil. Barry shows in this article that the holes in Martian stones may have formed this way as similar stones holes in Earth. Below is image from Mars by Viking 2, showing a stone with possible dissolution cavities. In Curiosity Sol-514 image, we can think about how the stone would look like if the white parts would be away.

Mars Meteorites

The study of meteorites from Mars has given interesting indications of life on Mars. See Astrobiology Magazine 19 August 2014, about a Mars-meteorite which fell to Nakhla, Egypt, year 1911: Life on Mars? Implications of a newly discovered mineral-rich structure. And the original publication by Elias Chatzitheodoridis 2014: A Conspicuous Clay Ovoid in Nakhla: Evidence for Subsurface Hydrothermal Alteration on Mars with Implications for Astrobiology .Elias and his group have investigated an oval shaped structural object(image below) which they found inside this Mars meteorite. It may be an ancient primitive Martian lifeform, which is handled in chapter 4.4 of the study linked above.

Also interesting article is Matt Williamson 2014: Meteorite May Contain Proof of Life on Mars, Researchers Say . In this article Philippe Gillet, director of EPFL’s Earth and Planetary Sciences Laboratory, describes the Tissint meteorite which fell on Morocco 2011. This meteorite originated from Mars 700000 years ago, and analysis shows that it contains organic carbon, which is very probable of biological origin in Mars.