Evidence of Life on Mars? - PART II
R. Gabriel Joseph1, Regina S. Dass2, V. Rizzo3,
N. Cantasano4, G. Bianciardi5
14. Evidence of Martian Algae/Cyanobacteria
Several investigators, based on an examination of photos of Martian specimens, have suggested that what appears to be algae may be present on Mars (Joseph 2014; Krupa 2018 Levin, Straat, & Benton, 1978). Levin et al (1978) upon closely examining photos from the 1976 Viking mission, observed what appeared to be green patches on Mars rocks which, over time, changed in size. Levin, Straat and Benton (1978) argued that changes in the green patches could represent biological activity and evidence of life (e.g. algae), or alternatively, green-colored dirt and dust.
In 2017, T. A. Krupa presented evidence at the Lunar and Planetary Society of what may be green photosynthetic organisms, e.g. algae. Krupa performed a detailed analysis of low albedo, "anomalous" images from Columbia Hills in Gusev Crater, and those photographed by the Spirit Rover's Pan Cam in an area of Mars dubbed "Larry's Outcrop/Larry's Lookout." These photos were initially analyzed by employing "red," "blue," and "green" filters, which were "radiometrically corrected with the radiance correction parameters found in the image file header." These images were analyzed next with a computer Geographic Information System, SAGA.
Krupa (2017) reported the analysis revealed what appears to be water pathways which may intermittently fill with water and that "the hillside at Larry's outcrop is covered by a very thin layer of green material" and "green spherules" which clearly resembles algae in the soil. Krupa (2017) concluded "that these spherules are a life form supported by that water.... and their green color suggests that the spherules contain a photosynthetic compound similar to green chlorophyll...The distribution of these spherules in a single layer...is also consistent with the hypothesis that the spherules are photosynthetic life forms," e.g., algae/cyanobacteria.
Krupa's (2017) computerized analyses which revealed possible water pathways that may intermittently fill with water, is, of course an unproven hypothesis, but which is nevertheless consistent with findings of Martian water by Renno et al., (2009) and other investigators. Specifically, in 2004 the European Space Agencies' Mars orbiter found evidence of water ice and detected vapors of water molecules via an infrared camera aboard the Mars Express spacecraft which was circling the Red Planet's south pole whereas additional "water" "anomalies" were reported in 2015 (Villanueva et al. 2015).
15. Biology of Seasonal Fluctuations in Martian Methane
If prokaryotes and fungi contributed to the formation of Martian sedimentary structures billions of years in the past, the accumulation of these decaying organisms should also be a source of sedimentary and atmospheric methane. As based on simulation studies (Tarasashvili et al., 2013), methanogens can flourish in a Mars-like environment. If methanogens have colonized Mars, they too would be a source of methane. In fact, high levels of methane have been detected at ground level and in the atmosphere of Mars and which varies in concentration depending on the season and which is continually replenished (Formisano et al. 2004; Mumma et al. 2004, 2009; Webster et al. 2013, 2015, 2018).
Specifically, it has been determined that Martian atmospheric methane levels are punctuated by major spikes in concentration which later decline, only to later increase again (Formisano et al. 2004; Mumma et al. 2004, 2009; Webster et al. 2018). Three separate methane plumes consisting of 19,000 metric tons of methane gas were detected in the Martian atmosphere by Europe's Mars Express spacecraft in 2003 (Formisano et al. 2004). Employing infrared spectrometers on three Earth-based telescopes several possible methane emission sources were found in the vicinity of Syrtis Major, Arabia Terra, and Nili Fossae in the southern and northern hemispheres (Formisano et al. 2004; Mumma et al. 2004).
In July of 2013, "an upper limit of 2.7 parts per billion of methane" was detected in the vicinity of the Gale Crater fluctuating between a value of 0.18 ppbv to 1.3 ppbv as measured on September of 2013 (Webster et al. 2013). A "tenfold spike" in methane levels followed with increases in late 2013 and early 2014, averaging "7 parts of methane per billion in the atmosphere" (Webster et al. 2015).
In 2018, Webster and colleagues reported that "in situ measurements at Gale crater made over a five-year period by the Tunable Laser Spectrometer on the Curiosity rover "revealed a strong, repeatable seasonal variation...which is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle." According to Webster et al (2018), the findings "are consistent with small localized sources of methane released from Martian surface or subsurface reservoirs."
On Earth, 90% of methane is produced biologically by living and decaying organisms (U.S. Department of Agriculture 2017; U.S. Department of Energy, 2017) and released as a waste product by prokaryotes (Bruhn et al. 2012; Kepler et al. 2006) and certain species of fungi (Lenhart et al. 2012; Liu et al 2015; Mukhin & Voronin, 2007). Terrestrial atmospheric methane levels also vary with the seasons and are directly attributed to biological activity.
For example, Rasmussen and Khalil (1981) found "stable seasonal cycles with peak concentrations in October and minimum concentrations in July." In 1983 these investigators reported that in the southern hemisphere the lowest concentrations are found during the late Australian summer and fall; likewise, there is less atmospheric methane in the northern hemisphere during summer. These seasonal variations have as their source biological activity in wetlands (Chen et al. 2008; Whalen 2005) and on farms and in rice paddies, just prior to harvest (Chen et al. 2008; Cicerone et al. 1983).
Chen et al. (2008) report a direct correlation between atmospheric methane and the growing seasons (14.45 mg CH4 m-2 h-1 [0.17 to 86.78 mg CH4 m-2 h-1) vs non-growing seasons (0.556 mg CH4 m-2 h-1 (0.002 to 6.722 mg CH4 m-2 h-1). Major contributing factors include surface temperatures, standing water depths, and the degree of plant growth, whereas in anerobic environments the absence of oxygen and the amount of degradable material are controlling influences.
Based on a thorough review of the evidence, Whalen (2005) determined that "emission from wetlands is also a significant component of the atmospheric CH4 budget...about 25% of total emissions from all anthropogenic and natural sources." Much of "this methane is produced by subsurface, anaerobic methanogenic bacteria and surficial oxidation by methanotrophic bacteria."
As documented in this report, methanogens, cyanobacteria, fungi, and lichens can easily survive in a Mars-like environment. Further there is evidence that these same species of prokaryote and eukaryotes have colonized Mars and that there is water beneath and above the surface.
Although considered controversial, NASA's 1976 Viking Labeled Release (VLR) studies, at two landing sites 4,000 miles apart on Mars, detected evidence of surface biological activity that could be attributed to fungi, lichens, algae, and a variety of prokaryotes (Levin & Straat, 1976, 1977, 1979a,b, 2016). In 2009 Levin and Straat also argued that perhaps 25% of the gasses released during the experiments could have been methane attributed to methanogens.
It is also well established that fungi and stromatolite-building cyanobacteria (algae) produce and are sources of methane (Hansson 1983; Klassen et al. 2017; Lenhart et al. 2012). Fungi and other eukaryotes generate methane via interactions with methanogenic archaea (see Olsson et al. 2017).
Algae and Saprotrophic fungi also produce methane independently of archaea (Hansson 1983; Klassen et al. 2017; Lenhart, et al. 2012) whereas fungal (and archaea) methane production is inhibited by the presence of oxygen and increases with increased levels of carbon dioxide (Lenhart, et al. 2012)--a finding which is true for most methane-producing species. Therefore, Mars is an ideal habitat for methanogens as there are minimal levels of free oxygen and the atmosphere is 96% carbon dioxide (Mahaffy et al. 2013), whereas the electron acceptor in methanogenesis is carbon dioxide.
Martian radiation may also promote the biological production of methane. It has been established that saprotrophic micro-fungi biologically decompose carbon-based radioactive debris from the damaged Chernobyl nuclear reactor (Zhdanova et al., 1991). Saprotrophic fungi are even adapted for accumulation and uptake of radiocesium fallout (Dighton et al. 1991) and, as noted, are a source of methane (Lenhart, et al. 2012). As indicated by Figures 8, 9, 10, 12, there is evidence of Martian fungal growth. Hence, it would be expected that the growth and biological activity of any Martian organisms might wax and wane, thereby resulting in a waxing and waning of Martian methane and contributing to seasonal variations.
Using Earth as an example, the most probable contributors to seasonal variations in Martian methane emissions are variations in water availability, temperature, degradable and methanogen biomass and the growth and decay of various organisms. As there no evidence of any significant abiotic methane production on Mars (Khayat et al. 2017; Roos-Serote et al. 2016; Webster et al. 2018), and given that 90% of terrestrial methane is biological in origin, it is reasonable to assume biological activity is the primary source of fluctuating levels of and seasonal variations in Martian methane.
16. Geology of Martian Methane?
Certainly, and as most investigators insist, it is possible that Martian methane is produced geologically and through abiogenic processes. Perhaps Martian methane is vented periodically and naturally released via gas permeable fissures; faults and fractures in rocks; sandstone and sediment; and the leakage of deep gas reservoirs through geothermal activity, and especially through vents leading deep beneath the surface from inactive mud-volcanoes as these are the source of abiogenic methane on Earth (U.S. Department of Energy, 2017; Etiope & Klusman 2002; Vanneste et al. 2001).
Khayat and colleagues (2017), however, searching for geological sources found none. Khayat et al. (2017) examined two volcanic districts via a high resolution spectrometer at NASA's Infrared Telescope Facility and using the high resolution heterodyne receiver at the James Clerk Maxwell Telescope facility, and "no active release of such gasses was detected."
Organic molecules are also a source of terrestrial methane (U.S. Department of Energy, 2017) and several investigators have reported what may be trace amounts of organic molecules on the surface of Mars (Ming et al. 2009; Sutter et al. 2016) which has been attributed to material deposited by meteors and dust drifting down from space (Frantseva et al. 2018; Moores & Schuerberg 2012; Schuerger et al. 2012). Therefore, it's been argued, Martian methane is produced by comets and meteors and via the UV photolysis of the minimal amounts of organic carbon drifting down upon the surface (Fries et al. 2015; Keppler et al. 2012).
However, as determined by Webster et al. (2018) these scenarios cannot account for the variations, levels and amount of methane so far detected which are far "greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle." Furthermore and as summed by Roos-Serote, Atreva, Webster and colleagues (2016), "We find no compelling evidence for any correlation between atmospheric methane and predicted meteor events."
Moreover, UV photolysis of Martian organic carbon is carbon-limited and constrained by the accretion rate of IDP organics (Moores & Schuerberg 2012). There is insufficient carbon on the surface (Bieman et al. 1976; Ming et al. 2009) to account for the varying and large concentrations of methane which are periodically pumped into the Martian atmosphere (Moores & Schuerberg 2012). And, organics buried one to two mm below ground would not be subject to UV photolysis, and any methane could only be liberated biologically (U.S. Department of Energy, 2017; U.S. Department of Agriculture 2017).
Certainly there is a likely abiogenic contribution to Martian methane. However, as on Earth, that contribution appears to be minimal. By contrast, there is evidence of biological activity, including the growth of what appears to be fungi, algae and lichens, on the Martian surface; and on Earth 90% of methane is biological in origin. Thus, the most logical, scientific explanation for the replenishment of and seasonal fluctuations in Martian methane is biological activity--the first evidence of which may have been discovered by the Viking Labeled Release experiments (Klein et al. 1976; Levin 2010; Levin & Straat 1976, 2009, 2016).
17. The Viking Labeled Release Experiment Detects Biological Activity on Mars?
As summarized by Levin (2010; Levin & Straat 2016), the Viking Labeled Release (LR) experiments were designed to detect biological activity on Mars. Thousands of field tests were performed and it was proved the LR experiment was capable of accurately detecting a very wide range of microorganisms including aerobic, anaerobic, and facultative bacteria, as well as lichens, fungi, and algae.
Once on Mars a nutrient containing radioactive carbon was added to a Martian soil sample and the presence of radioactivity in the gasses released served as evidence of active metabolism. A control experiment heat-treated a second sample to kill microorganisms. Positive results including evidence of biological metabolism were obtained from the raw sample which was not subject to extreme heat-sterilization. By contrast, when soil samples were heated to 50°C, biological activity decreased by 65%. When Martian soil was pre-heated to 160°C there was no evidence of biology. When two samples of Martian soil were stored at approximately 10°C for long time periods there was a 90% and 100% reduction in activity. When not subject to sterilization, robust evidence of biological metabolism and increases in activity were obtained (Klein et al. 1976). As described by Levin and Straat (2016), the LR instruments operated flawlessly on Mars. Both Viking landing sites, some 4,000 miles apart, produced strong responses and met the pre-mission criteria for the detection of life.
To distinguish between non-biological and biological agents, additional experiments were executed via commands from Earth. Each such ad hoc series of tests again demonstrated on-going Martian metabolism. Four different LR experiments were conducted, each of which yielded positive results, and five controls, all of which supported the positive results as biological.
Levin concluded that the "amplitudes and kinetics of the Mars LR results were similar to those of terrestrial results, especially close to those of soils in, or from, frigid areas," and that the LR experiment had found evidence of biological activity on Mars (Levin 2010; Levin & Straat 1976, 1979a,b, 2016).
The results, however, were rejected by NASA administrators who argued that since the addition of more nutrients into the soil temporarily decreased the level of biological activity "the LR therefore had not detected life on Mars, but had detected a chemical or physical agent that had produced false positive results" (Levin 2010). NASA's arguments (detailed on the NASA/Mars website), though interesting, are not based on factual evidence, but post-hoc theorizing and the interested reader is encouraged to review NASA's claims to arrive at their own conclusions. In fact, according to Levin (2010) "NASA-bonded Antarctic soil 664 had reacted to its second injection as had the Martian soils" and "the decline in gas level was caused by re-adsorption of the evolved gas into the dampened soil." That only trace amounts of carbon and organic molecules have been detected on Mars (Bieman et al. 1976, 1977; Ming et al. 2009; Sutter et al. 2016) also does not support NASA's physical-chemical-false-positive hypothesis.
Subsequently, Bianciardi, Miller, Straat, and Levin (2012) performed a mathematical complexity deep analysis of the Viking LR data, employing seven complexity variables. It was determined that the Viking LR positive responses demonstrated a different pattern from control responses which resembled near-random noise. By contrast, the active experiments exhibited highly organized responses typical of biology.
18. Caveats and Conclusions
We have presented a body of observations and evidence which supports the hypothesis Mars may have been, and may still be, a living planet. Although disagreements and differing interpretations and hypotheses abound, there is no factual, scientific evidence proving or even strongly supporting a purely abiotic explanation for the data and observations presented here which we believe favors biology. Thus, the null hypothesis is rejected.
Admittedly, abiogenic factors can't be ruled out. Conversely, at present, there is no microscopic evidence depicting cells or intra-cellular structure and thus no definitive proof of Martian life. Moreover, although organisms can survive in space or in simulated Mars-like environments, there is no proof they can flourish on Mars. It is also very difficult to distinguish, with a high level of confidence, between what may be living organisms vs sedimentary structures. Similarities in morphology are not proof. In many respects the observations presented here could be described as circumstantial and do not rise to the level of "extraordinary evidence" thus precluding "extraordinary claims." Although, collectively, the evidence, in total, weighs in favor of biology, we can only conclude that the question of life on Mars remains unanswered.
Peer Review and Recommendations
Fourteen qualified experts (eight Senior Editors and six independent
scientists) refereed and peer reviewed "Evidence of Life on Mars?" Eleven
experts in total recommended publication and of the eight Editors three
rejected the article. The experts have a publication history in the
following areas of science: Microbiology, Biochemistry, Biogeology,
Mars Viking Experiments, Fungi, Lichens, Methanogens, Extremophiles,
Mars-Simulated Environments, Martian Atmosphere, Martian Meteors,
Radiation Biology.
TOTAL: 11 Yes / 3 No
Supervised and Verified by the Managing Editor
D. Anderson
February 28, 2019
Journal of Astrobiology and Space Science Reviews
http//JournalofAstrobiology.com
{ http://journalofastrobiology.com/LifeonMarsPressRelease.html }
Evidence of Life on Mars? - PART II
