The properties near-surface cometary atmosphere is considered, as mediums, in which the formation of ordered structures from charged microparticles is possible. Based on dates on cometary atmospheres and guesses of mechanisms of charging of sublimating microparticles the calculations of an electric field near to a surface of a comet are executed. The electric field strength is determined by a charge of large particles (20 ... 50 micrometer) also reaches values 500 V/m. In such conditions in a near-surface atmosphere of a comet, the discharges similar to the discharges in high layers of an Earth's atmosphere are possible. The estimates of parameters of dusty plasma are made. This plasma will have properties, close to properties of laboratory dusty plasma, in which formation ordered structures from charged microparticles is explored. It is shown, that there are requirements for development of processes of a self-compression of dusty plasma of a cometary atmosphere, that is an incipient state forming of ordered structures. Thus, the near-surface atmospheric layer represents unique medium, in which one alongside with existence prebiotic conditions, there are conditions for development of processes of self-organization of structures, which one afterwards can be used as a template for prebiological structures.
Proc. SPIE 4137, Meteorites and microbes: meteorite collection and ice sampling at Patriot Hills, Thiel Mountains, and South Pole, Antarctica, 0000 (29 December 2000); https://doi.org/10.1117/12.411617
In 1998, the Patriot Hills area of the Ellsworth Mountains of Antarctica was selected by the Planetary Studies Foundation (PSF) of Algonquin, Illinois USA as a potential site for the collection of meteorites. The eight person expedition searched several sites in and around the Patriot Hills, but met with little success in finding meteorites. In January 2000, the PSF chose to continue its efforts in the Thiel Mountains, an area of known meteorite concentrations. The goal was to collect as many meteorites as possible by extending the previously searched blue ice areas at the Moulton Escarpment. Earlier search teams collectively recovered 36 meteorites. In the five days of fieldwork at the Moulton Escarpment, the PSF team collected 19 confirmed stone meteorites, and 2 possible achondrites. Upon return to Patriot Hills another small stone meteorite, consisting of 6 small fragments totalling 1.7 grams, was collected in the Morris Moraine where a 23 mg meteorite fragment was found in 1998. In addition, ice samples were collected at Patriot Hills, Thiel Mountains, and the South Pole. The presence of several micro-organisms has been identified in these samplings and will be evaluated as possible contaminants of Antarctic meteorites.
Comparative analysis of bio-organisms and mineral individuals provides a bulk of evidence for biomineral homologies at the morphological, functional, ontogenetic, phylogenetic, and paragenetic levels and mineral predetermination of many features and functions traditionally viewed as purely biological. Highly-structured solid hydrocarbons (bitumens) and highly carbonaceous substances provide best homologies with simplest biological organisms. The physico-chemical conditions of ordered hydrocarbon condensation are similar to the theoretical origin-of-life conditions. It has been shown that protein amino acids are produced during crystallization and thermal ordering of hydrocarbons as well as by means of radioactive synthesis, which suggests mineral-based genesis of primitive biofunctioning structures and hydrocarbon mineral individuals with structures and functions of proto-organisms. These experimental data underlie our concept of hydrocarbon crystallization of life and mineral organismo-biosis. Biomineral homologies and the associated convergence of properties of bio-organisms and hydrocarbon minerals constitute the greatest obstacle hindering identification of biomorphous problematica, because, on the one hand, their biochemical components are easily destroyed under conditions of even low-grade metamorphism and, on the other hand, almost all compounds referred to as biological ones are synthesizable in the abiogenic way under natural conditions. So one should look for biomarkers relying on their structural and morphological features rather than biochemical ones, because the major elements of the bio-organisms's form and structure can be inherited by the fossilized product.
The instrumentation on the 60 kg Beagle 2 lander for ESA's 2003 Mars Express mission will be described. Beagle 2 will be search for organic material on and below the surface of Mars in addition to a study of the inorganic chemistry and mineralogy of the landing site. The lander will utilize acquisitions and preparation tools to obtain samples from below the surface, and both under and inside rocks. In situ analysis will include examination of samples with an optical microscope, Mossbauer and fluorescent X-ray spectrometers. Extracted samples will be returned to the lander for analysis, in particular a search for organics and a measurement of their isotopic composition. The experiment configuration and design will be described along with the status of the project.
After 21 years of study, a case was made that the 1976 Viking Labeled Release (LR) experiment detected microbial life in the Martian soil. However, two key factors prevent general acceptance of that conclusion. They are the failure of the Viking Gas Chromatograph Mass Spectrometer (GCMS) to find organic matter in the Martian soil; and the presumed inability of the Martian environment to support liquid water. Further examination of these often cited factors shows they do not prohibit a biological interpretation of the Mars LR results. Newly revealed information on tests made with the Viking GCMS Engineering Breadboard instrument (EBB/GCMS) attests to its inability to detect organic matter in some terrestrial soils. New work also shows that organic matter from moderate populations of micro-organisms in soil would have been undetectable. These qualifications of the Viking GCMS weaken its historical impact against a biological interpretation of the LR Mars data. The no-liquid-water argument is also shown to be flawed. Empirical data demonstrate that water does exist in liquid phase under ambient atmospheric pressures and temperatures existing on the surface of Mars. NASA's June 22 press conference announcement that the Mars Global Surveyor found extensive evidence of current liquid water on Mars adds ground truth validation. The July 10, 2000, report of indigenous micro-organisms fully metabolizing in sub-freezing South Pole snow where little, if any, water is available, demonstrates the possibility for life on Mars. A leap of faith is no longer required concerning the possibility of indigenous micro-organisms on Mars. The present hiatus from Martian exploration provides an excellent opportunity to mine and analyze data relevant to life on Mars, and to conduct meaningful experiments. An available flight type Viking GCMS can be tested to determine its sensitivity to organic matter, including micro-organisms, and provide guidance in designing future Martian organic detection instruments. Experiments could determine whether terrestrial micro-organisms could survive or grow under Martian conditions as they are now known. This could be done in combination with experiments further determining the limiting conditions of liquid water on Mars. A simple metabolic chirality experiment, based on the LR legacy, is advocated for the next Mars lander. The experiment could determine unequivocally whether living microbes exist in the soil of Mars. Suggestions for further research and development of life detection and analysis experiments are made.
On Earth, according to conventional theory, the largest, by mass and volume, identifiable trace of past life is subsurface oil and natural gas deposits. Nearly all coal and oil on Earth and most sedimentary source rocks associated with coal, oil, and natural gas contain molecules of biological origin and is proof of past life. If Mars possessed an Earth-like biosphere in the past, Mars may contain subsurface deposits of oil and natural gas indicating past life. Life might still exist in these deposits. Subsurface oil and natural gas on Mars would probably cause seepage of hydrocarbon gases such as methane at favorable locations on the Martian surface. Further, if Mars contains substantial subsurface life, the most detectable signature of this life on the Martian surface would be gases generated by the life percolating up to the surface and venting into the Martian atmosphere. In this paper, systems that can detect evidence of subsurface oil and gas, including ground penetrating radar and infrared gas sensors are explored. The limitations and future prospects of infrared gas detection and imaging technologies are explored. The power, mass, and volume requirements for infrared instruments able to detect venting gases, especially methane, from an aerobot is estimated. The maximum range from the infrared sensor to the gas vent and the minimum detectable gas density or fraction of the Martian atmosphere - as appropriate for the instrument type - is estimated. The bit rate and bit error rate requirements for transmitting the data back to Earth are also estimated.
A network of three longitudinally-spaced robotic imaging telescopes is described. So far planets have been
found only around bright stars (m < 1Om). Employment of the network and the photometric method for the detection of extrasolar planets will lead to the discovery of planets around stars of much fainter magnitudes
(m < 19m).
The samples returned from the lunar surface by Apollo were devoid of organic material, an observation that satisfied the scientific community that the Moon is irrelevant to the topic of life in the universe. However, the equatorial regions of the Moon sampled by Apollo and Luna are not representative of the Moon as a whole. The lunar poles harbor a microenvironment which possess conditions utterly unlike those of the lunar equator. These conditions may allow in situ production of organics on the Moon from indigenous inorganic material. If this is the case, the Moon may allow field-testing of models of inorganic synthesis which have been invoked for many surfaces in the solar system, and even interstellar clouds.
Microbial life is found all over the globe. Diverse communities are even found in such places in which extreme conditions with respect of temperature, salinity, pH, and pressure prevail. Many of these environments were until recently considered too harsh to harbor microbial life. The microorganisms adapted to an existence at the edge of life are termed extremophiles. They include members of the Prokaryotes (domains Archaea and Bacteria) and the Eukarya, including algae and protozoa. Extremophilic microbes thrive at low and high temperatures -from subzero levels to above the boiling point of water, at both sides of the pH scale - in acidic as well as in alkaline media, in hypersaline environments with salt concentrations of up to saturation, at high pressure, both in the deep sea and in the terrestrial deep subsurface where they are exposed to pressures of hundreds of atmospheres, and in other extreme conditions. In many cases they tolerate combinations of more than one environmental stress factor. Some of these extremophiles may be considered as "living fossils" since their environment resembles the conditions that may have existed during the time life arose on Earth, more than 3.5 billion years ago. In view of these properties the extremophilic microorganisms may be considered as model organisms when exploring the possibilities of the existence of extraterrestrial life. For example, the microbes discovered in ice cores recovered from the depth of the Lake Vostok in Antarctica may serve as a model simulating conditions prevailing in the permafrost subsurface area of Mars or Jupiter's moon Europa. Microbial life in the Dead Sea or in Great Salt Lake may resemble halophilic life forms that may exist elsewhere in the universe, adapted to life at low water activities. Likewise, hyperthermophilic microorganisms present on Earth in hot springs, hydrothermal vents and other sites heated by volcanic activity in terrestrial or marine areas, may resemble life forms that may exist on hot planets such as Venus.
Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Some can use alternative electron acceptors such as nitrate, fumarate, dimethylsulfoxide or trimethylamine-N-oxide Halobacterium salinarum can also grow fermentatively on L-arginine, and bacteriorhodopsin-containing cells may even grow anaerobically, energized by light. Obligatory anaerobic halophilic methanogenic Archaea also exist. The bacterial domain contains many anaerobic halophiles, including sulfate reducers. There is also a group of specialized obligatory anaerobic Bacteria, phylogenetically clustering in the low G+C branch of the Firmicutes. Most representatives of this group (order Haloanaerobiales, families Haloanaerobiaceae and Halobacteroidaceae) are fermentative, using a variety of carbohydrates and amino acids. One species combines the potential for anaerobic growth at high salt concentrations with a preference for high temperatures. Others are homoacetogens; Acetohalobium arabaticum can grow anaerobically as a chemolithotroph, producing acetate from hydrogen and CO2. The Haloanaerobiales accumulate high concentrations of K+ and Cl- in their cytoplasm, thereby showing a strategy of salt adaptation similar to that used by the Halobacteriales. Recently a new representative of the Haloanaerobiales was isolated from bottom sediments of the Dead Sea (strain DSSe1), which grows anaerobically by oxidation of glycerol to acetate and CO2 while reducing selenate to selenite and elementary selenium. Other electron acceptors supporting anaerobic growth of
this strain are nitrate and trimethylamine-N-oxide. The versatility of life at high salt concentrations with respect to the variety of substrates used, the types of dissimilatory metabolism, and the diversity of potential electron acceptors has important implications for the potential for life in hostile environments lacking oxygen and high in salt, implications that may also be
relevant to astrobiology.
A workshop was held (10/99) for high school students and teachers on astrobiology. NASA provided support through an IDEAS grant. Out of 63 qualified applicants, 29 were accepted: 22 students (11 minorities) and 7 teachers. The workshop was held on 2 successive weekends. Activities included: culturing microbes from human skin, discussing "what is life?", building and using a 2-inch refractive telescope and a van-Leeuwenhoek-type microscope (each participant built and kept them), listening to lectures by Dr. Richard Gelderman on detecting extra solar planets and by Dr. Richard Hoover on life in extreme environments. Other activities included: collecting samples and isolating microorganisms from the lost river cave, studying microbial life from extreme environments in the laboratory, using the internet as a research tool and debating the logistics and feasibility of a lunar colony. Written evaluations of the workshop led to the following conclusions: 48% of the students considered a possible career in the biological and/or astrophysical sciences, and half of these stated they were spurred on by the workshop itself.