Astrobiological Implications Research Articles

Survival of Moss Reproductive Structures under Simulated Martian Environmental Conditions and Extreme Thermal Stress: Vibrational Spectroscopic Study and Astrobiological Implications

The principal goal of astrobiology is the search for extraterrestrial life forms. A key aspect is the study of the ability of different kinds of terrestrial organisms to support simulated extraterrestrial environmental conditions. Mosses are multicellular green plants, poorly studied from an astrobiological perspective. In this paper, we report experimental results obtained using two species of moss, which demonstrate that both the spores of the moss Funaria hygrometrica as well as the desiccated vegetative gametophyte shoots of the moss Tortella squarrosa (Pleurochaete squarrosa) were capable of resisting Simulated Martian Environmental Conditions (SMEC): Mars simulated atmospheric composition 99.9% CO2, and 0.6% H2O with a pressure of 7 mbars, -73 oC and UV irradiation of 30 mW cm-2 in a wavelength range of 200-400 nm under a limited short time of exposition of 2 hours. After being exposed to SMEC and then transferred to an appropriate growth medium, the F. hygrometrica spores germinated, producing typical gametophyte protonemal cells and leafy shoots. Likewise, detached leaves from SMEC-exposed gametophyte shoots of T. squarrosa retained the ability to produce new protonemata and shoots under suitable growth conditions. Furthermore, we studied the tolerance of these moss structures to a thermal stress of 100 °C for 1 h; in both cases the spores and shoots were capable of resisting this heat treatment. Our study using FT-Raman and FT-IR vibrational spectroscopy demonstrated that neither spores nor shoots apparently suffered significant damage in their biomolecular makeup after being subject to these stress treatments. The implications of these findings for the search of life on Mars are discussed.

Abiotic methane seepage in the Ronda peridotite massif, southern Spain

Abiotic methane in serpentinized peridotites (MSP) has implications for energy resource exploration, planetary geology, subsurface microbiology and astrobiology. Once considered a rare occurrence on Earth, reports of MSP are increasing for numerous localities worldwide in low temperature, land-based springs and seeps. We report the discovery of six methane-rich water springs and two ponds with active gas bubbling in the Ronda peridotite massif, in southern Spain. Water is hyperalkaline with typical hydrochemical features of active serpentinization (pH: 10.7 to 11.7, T: 17.1 to 21.5 °C, Ca–OH facies). Dissolved CH4 concentrations range from 0.1 to 3.2 mg/L. The methane stable C and H isotope ratios in the natural spring and bubbling sites (δ13CCH4: −12.3 to −37‰ VPDB; δ2HCH4: −280 to −333‰ VSMOW) indicate a predominant abiotic origin. In contrast, springs with manmade water systems, i.e., pipes or fountains, appear to have mixed biotic-abiotic origin (δ13CCH4: −44 to −69‰; δ2HCH4: −180 to −319‰). Radiocarbon (14C) analyses show that methane C in a natural spring is older than ca. 50,000 y BP, whereas dissolved inorganic carbon (DIC) analysed in all springs has an apparent 14C age ranging from modern to 2334 y BP. Therefore most, if not all, of the CH4 is allochthonous, i.e., not generated from the carbon in the hyperalkaline water. Methane is also released as bubbles in natural ponds and as diffuse seepages (∼101–102 mg CH4 m−2d−1) from the ground up to several tens of metres from the seeps and springs, albeit with no overt visual evidence. These data suggest that the gas follows independent migration pathways, potentially along faults or fracture systems, physically isolated from the hyperalkaline springs. Methane does not seem to be genetically related to the hyperalkaline water, which may only act as a carrier of the gas. Gas-bearing springs, vents and invisible microseepage in land-based peridotites are more common than previously thought. In addition to other geological sources, MSP is potentially a natural source of methane for the troposphere and requires more worldwide flux measurements.

Reactions of Azine Anions with Nitrogen and Oxygen Atoms: Implications for Titan's Upper Atmosphere and Interstellar Chemistry.

Azines are important in many extraterrestrial environments, from the atmosphere of Titan to the interstellar medium. They have been implicated as possible carriers of the diffuse interstellar bands in astronomy, indicating their persistence in interstellar space. Most importantly, they constitute the basic building blocks of DNA and RNA, so their chemical reactivity in these environments has significant astrobiological implications. In addition, N and O atoms are widely observed in the ISM and in the ionospheres of planets and moons. However, the chemical reactions of molecular anions with abundant interstellar and atmospheric atomic species are largely unexplored. In this paper, gas-phase reactions of deprotonated anions of benzene, pyridine, pyridazine, pyrimidine, pyrazine, and s-triazine with N and O atoms are studied both experimentally and computationally. In all cases, the major reaction channel is associative electron detachment; these reactions are particularly important since they control the balance between negative ions and free electron densities. The reactions of the azine anions with N atoms exhibit larger rate constants than reactions of corresponding chain anions. The reactions of azine anions with O atoms are even more rapid, with complex product patterns for different reactants. The mechanisms are studied theoretically by employing density functional theory; spin conversion is found to be important in determining some product distributions. The rich gas-phase chemistry observed in this work provides a better understanding of ion-atom reactions and their contributions to ionospheric chemistry as well as the chemical processing that occurs in the boundary layers between diffuse and dense interstellar clouds.

N- ANDO-HETEROCYCLES PRODUCED FROM THE IRRADIATION OF BENZENE AND NAPHTHALENE IN H2O/NH3-CONTAINING ICES

Aromatic heterocyclic molecules are an important class of molecules of astrophysical and biological significance that include pyridine, pyrimidine, and their derivatives. Such compounds are believed to exist in interstellar and circumstellar environments, though they have never been observed in the gas phase. Regardless of their presence in the gas phase in space, numerous heterocycles have been reported in carbonaceous meteorites, which indicates that they are formed under astrophysical conditions. The experimental work described here shows that N- and O-heterocyclic molecules can form from the ultraviolet (UV) irradiation of the homocyclic aromatic molecules benzene (C6H6) or naphthalene (C10H8) mixed in ices containing H2O and NH3. This represents an alternative way to generate aromatic heterocycles to those considered before and may have important implications for astrochemistry and astrobiology.

Deprotonated purine dissociation: experiments, computations, and astrobiological implications.

A central focus of astrobiology is the determination of abiotic formation routes to important biomolecules. The dissociation mechanisms of these molecules lend valuable insights into their synthesis pathways. Because of the detection of organic anions in the interstellar medium (ISM), it is imperative to study their role in these syntheses. This work aims to experimentally and computationally examine deprotonated adenine and guanine dissociation in an effort to illuminate potential anionic precursors to purine formation. Collision-induced dissociation (CID) products and their branching fractions are experimentally measured using an ion trap mass spectrometer. Deprotonated guanine dissociates primarily by deammoniation (97%) with minor losses of carbodiimide (HNCNH) and/or cyanamide (NH2CN), and isocyanic acid (HNCO). Deprotonated adenine fragments by loss of hydrogen cyanide and/or isocyanide (HCN/HNC; 90%) and carbodiimide (HNCNH) and/or cyanamide (NH2CN; 10%). Tandem mass spectrometry (MS(n)) experiments reveal that deprotonated guanine fragments lose additional HCN and CO, while deprotonated adenine fragments successively lose HNC and HCN. Every neutral fragment observed in this study has been detected in the ISM, highlighting the potential for nucleobases such as these to form in such environments. Lastly, the acidity of abundant fragment ions is experimentally bracketed. Theoretical calculations at the B3LYP/6-311++G(d,p) level of theory are performed to delineate the mechanisms of dissociation and analyze the energies of reactants, intermediates, transition states, and products of these CID processes.

Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology.

In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings.

Spectral features of biogenic calcium carbonates and implications for astrobiology

AbstractThe ability to discriminate biogenic from abiogenic calcium carbonate (CaCO3) would be useful in the search for extant or extinct life, since CaCO3can be produced by both biotic and abiotic processes on Earth. Bioprecipitated CaCO3material was produced during the growth of heterotrophic microbial isolates on medium enriched with calcium acetate or calcium citrate. These biologically produced CaCO3, along with natural and synthetic non-biologically produced CaCO3samples, were analysed by reflectance spectroscopy (0.35–2.5 μm), Raman spectroscopy (532 and 785 nm), and laser-induced fluorescence spectroscopy (365 and 405 nm excitation). Optimal instruments for the discrimination of biogenic from abiogenic CaCO3were determined to be reflectance spectroscopy, and laser-induced fluorescence spectroscopy. Multiple absorption features in the visible light region occurred in reflectance spectra for most biogenic CaCO3samples, which are likely due to organic pigments. Multiple fluorescence peaks occurred in emission spectra (405 nm excitation) of biogenic CaCO3samples, which also are best attributed to the presence of organic compounds; however, further analyses must be performed in order to better determine the cause of these features to establish criteria for confirming the origin of a given CaCO3sample. Raman spectroscopy was not useful for discrimination since any potential Raman peaks in spectra of biogenic carbonates collected by both the 532 and 785 nm lasers were overwhelmed by fluorescence. However, this also suggests that biogenic carbonates may be identified by the presence of this organic-associated fluorescence. No reliable spectroscopic differences in terms of parameters such as positions or widths of carbonate-associated absorption bands were found between the biogenic and abiogenic carbonate samples. These results indicate that the presence or absence of organic matter intimately associated with carbonate minerals is the only potentially useful spectral discriminator for the techniques that were examined, and that multiple spectroscopic techniques are capable of detecting the presence of associated organic materials. However, the presence or absence of intimately associated organic matter is not, in itself, an indicator of biogenicity.

Analogy and the Societal Implications of Astrobiology

The impact of finding life beyond Earth, whether microbial, complex, or intelligent, is an important and timely problem given recent discoveries in the field of astrobiology. Analogy is one of the tools that may be used cautiously to explore potential impacts of discovering extraterrestrial life under different scenarios. After a brief examination of the problems and promise of analogy, this article suggests four analogs useful for providing guidelines in the event of such a discovery: the microbe analogy, the culture contact analogy, the transmission/translation analogy, and the worldview analogy. We offer what we term the “Goldilocks Principle of Analogy”: analogy must not be so general as to be meaningless, nor so specific as to be misleading. As in other fields, the middle “Goldilocks” ground is where analogies may serve as useful guideposts for astrobiology and its impact. And although the discovery of life beyond Earth will be a unique event, these guidelines may be useful for policy decisions both before and after the discovery of life.

A conspicuous clay ovoid in Nakhla: evidence for subsurface hydrothermal alteration on Mars with implications for astrobiology.

Abstract A conspicuous biomorphic ovoid structure has been discovered in the Nakhla martian meteorite, made of nanocrystalline iron-rich saponitic clay and amorphous material. The ovoid is indigenous to Nakhla and occurs within a late-formed amorphous mesostasis region of rhyolitic composition that is interstitial to two clinopyroxene grains with Al-rich rims, and contains acicular apatite crystals, olivine, sulfides, Ti-rich magnetite, and a new mineral of the rhoenite group. To infer the origin of the ovoid, a large set of analytical tools was employed, including scanning electron microscopy and backscattered electron imaging, wavelength-dispersive X-ray analysis, X-ray mapping, Raman spectroscopy, time-of-flight secondary ion mass spectrometry analysis, high-resolution transmission electron microscope imaging, and atomic force microscope topographic mapping. The concentric wall of the ovoid surrounds an originally hollow volume and exhibits internal layering of contrasting nanotextures but uniform chemical composition, and likely inherited its overall shape from a preexisting vesicle in the mesostasis glass. A final fibrous layer of Fe-rich phases blankets the interior surfaces of the ovoid wall structure. There is evidence that the parent rock of Nakhla has undergone a shock event from a nearby bolide impact that melted the rims of pyroxene and the interstitial matter and initiated an igneous hydrothermal system of rapidly cooling fluids, which were progressively mixed with fluids from the melted permafrost. Sharp temperature gradients were responsible for the crystallization of Al-rich clinopyroxene rims, rhoenite, acicular apatites, and the quenching of the mesostasis glass and the vesicle. During the formation of the ovoid structure, episodic fluid infiltration events resulted in the precipitation of saponite rinds around the vesicle walls, altered pyrrhotite to marcasite, and then isolated the ovoid wall structure from the rest of the system by depositing a layer of iron oxides/hydroxides. Carbonates, halite, and sulfates were deposited last within interstitial spaces and along fractures. Among three plausible competing hypotheses here, this particular abiotic scenario is considered to be the most reasonable explanation for the formation of the ovoid structure in Nakhla, and although compelling evidence for a biotic origin is lacking, it is evident that the martian subsurface contains niche environments where life could develop.

Synthesis and characterization of the Mars-relevant phosphate minerals Fe- and Mg-whitlockite and merrillite and a possible mechanism that maintains charge balance during whitlockite to merrillite transformation

Merrillite [Ca9NaMg(PO4)7] occurs as a dominant primary Ca-phosphate mineral in martian meteorites and therefore presumably also on Mars. The mineral is an important phase in exploring differences in geologic processes between Earth and Mars, and also has astrobiological implications due to its potential role as a significant source of the bio-essential nutrient phosphate. Merrillite does not occur terrestrially as a discrete mineral phase, making it difficult to obtain for Mars-relevant studies. It can, however, be synthesized from a similar terrestrial mineral, whitlockite (natural or synthetic), through dehydrogenation. Here we present methods for synthesizing relatively large quantities (0.5 g or greater per batch) of coarse crystalline (75 μm+) Mg-whitlockite, Fe-whitlockite, mixed Fe/Mg-whitlockites, and from these synthesized minerals produce Mg-merrillite, ferrous and ferric Fe-merrillite, and ferrous and ferric mixed Fe/Mg-merrillite. Chemistry and atomic structures of synthesized Fe- and mixed Fe/ Mg-whitlockite and ferrous and ferric Fe- and mixed Fe/Mg- merrillite resulting from single-crystal X-ray diffraction, infrared spectroscopy, and electron microprobe analyses are presented. We also present a mechanism for maintaining charge balance during the formation of merrillite from whitlockite. Our results shed light on these mineral structures for future martian studies, and provide methods for creating coarse crystalline merrillite for use in Mars-relevant thermodynamic, kinetic, soil/dust simulant, crystallographic, astrobiological, and other studies.

Enigmatic tubular features in impact glass

We describe the fi rst putative microbial trace fossils hosted in meteorite impact glass. We conducted optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy on postimpact tubular features hosted in impact glasses from the Ries impact structure (Germany). The morphologies of the tubules are inconsistent with known mineralogical crystallization mechanisms, and combined with evidence of organic molecules suggest that these tubules cannot be formed through purely abiotic processes. The simplest and most consistent explanation of the data is that biological activity played a role in the formation of the tubular textures in the Ries glasses, likely during postimpact hydrothermal activity. As impact glass is a ubiquitous substrate on rocky bodies throughout the Solar System and likely common on the early Earth, the preservation of biological activity in impact glass has signifi cant astrobiological implications for life on early Earth as well as for the search for life on other planets

Encountering life in the universe: ethical foundations and social implications of astrobiology

Encountering life in the universe: ethical foundations and social implications of astrobiology

The timing of alluvial activity in Gale crater, Mars

AbstractThe Curiosity rover's discovery of rocks preserving evidence of past habitable conditions in Gale crater highlights the importance of constraining the timing of responsible depositional settings to understand the astrobiological implications for Mars. Crater statistics and mapping reveal the bulk of the alluvial deposits in Gale, including those interrogated by Curiosity, were likely emplaced during the Hesperian, thereby implying that habitable conditions persisted after the Noachian. Crater counting data sets and upper Peace Vallis fan morphology also suggest a possible younger period of fluvial activation that deposited ~10–20 m of sediments on the upper fan after emplacement of the main body of the fan. If validated, water associated with later alluvial activity may have contributed to secondary diagenetic features in Yellowknife Bay.

Congruence of Coherence Peaks of Daily Geomagnetic Activity and Total Earthquakes with Mintaka's (Orion's Belt) 5.7 Day Periodicity: Potential Implications for Astrobiology

A single strong frequency-dependence was revealed by cross-spectral analysis between daily geomagnetic activity and total numbers of daily earthquakes between 2009 through 2013 that exhibited a 5.7 day cycle. We examined the potential for association with Mintaka's double star orbital periodicity of 5.73 days. Calculations of gravitational force and equivalent energies between the earth and Mintaka as well as the variations with orbital periodicity indicated reliable radiant flux densities upon the terrestrial surface in the order of 10 -11 W·m -2 . This is within the same order of magnitude as background photon emissions whose increase occurs conspicuously before major earthquakes and are related to geomagnetic activity. This magnitude of power has recently been measured from preparations of brain tissue and from human cerebrums while subjects sat in hyper-dark settings and engaged in imagination. The power density also matches the gravitational energy within a human brain mass from empirical measurements of the variation in G. The convergence of quantitative solutions suggests that shared periodicities from some very distant stellar objects may affect terrestrial processes assuming the power densities are congruent.

Surface interaction of L-alanine on hematite: an astrobiological implication.

In the present work, surface interaction of L-alanine (L-ala) has been investigated on hematite (α-Fe2O3), an abundant mineral on Mars, as a function of time (5 min-48 h), pH (4.0 and 6.20 ± 0.10) and concentration (1 × 10(-3) M-10 × 10(-3) M) with optical absorbance and energy-dispersive spectroscopy (EDS). Adsorption parameters (XM and KL) were calculated from Langmuir adsorption isotherms. L-alanine has maximum affinity (65.31 %) in its zwitterionic form at pH 6.20, while it is only 29.86 % adsorbed at pH 4.0. Possible astrobiological implications are discussed.

Habitable Zone Lifetimes of Exoplanets around Main Sequence Stars

The potential habitability of newly discovered exoplanets is initially assessed by determining whether their orbits fall within the circumstellar habitable zone of their star. However, the habitable zone (HZ) is not static in time or space, and its boundaries migrate outward at a rate proportional to the increase in luminosity of a star undergoing stellar evolution, possibly including or excluding planets over the course of the star's main sequence lifetime. We describe the time that a planet spends within the HZ as its "habitable zone lifetime." The HZ lifetime of a planet has strong astrobiological implications and is especially important when considering the evolution of complex life, which is likely to require a longer residence time within the HZ. Here, we present results from a simple model built to investigate the evolution of the "classic" HZ over time, while also providing estimates for the evolution of stellar luminosity over time in order to develop a "hybrid" HZ model. These models return estimates for the HZ lifetimes of Earth and 7 confirmed HZ exoplanets and 27 unconfirmed Kepler candidates. The HZ lifetime for Earth ranges between 6.29 and 7.79×10⁹ years (Gyr). The 7 exoplanets fall in a range between ∼1 and 54.72 Gyr, while the 27 Kepler candidate planets' HZ lifetimes range between 0.43 and 18.8 Gyr. Our results show that exoplanet HD 85512b is no longer within the HZ, assuming it has an Earth analog atmosphere. The HZ lifetime should be considered in future models of planetary habitability as setting an upper limit on the lifetime of any potential exoplanetary biosphere, and also for identifying planets of high astrobiological potential for continued observational or modeling campaigns.

Bacterial communities in Fe/Mn films, sulphate crusts, and aluminium glazes from Swedish Lapland: implications for astrobiology on Mars

AbstractRock coatings have been observed on Mars by Mars Pathfinder, Viking and the Mars Exploration Rovers. Although rock varnish has been studied for its potential as a biosignature, other types of rock coating have been largely ignored. In Kärkevagge, Swedish Lapland, sulphate crusts, aluminium glazes and Fe/Mn films occur with mineralogies mimicking those observed on the surface of Mars. Molecular analysis and scanning electron microscopy (SEM) were used to investigate the bacterial communities associated with these rock coatings. Molecular techniques revealed differences in community structure and metabolisms associated with the production of secondary minerals between the three coating types. SEM analysis showed evidence of encrustation in mineral coatings in the Fe/Mn films and aluminium glazes, and evidence of abundant microbial communities in all three coating types. These observations provide evidence for bacterial participation in the genesis of rock coatings. For astrobiology on Mars, rock coatings are an attractive biosignature target scientifically and logistically: they are surface environments easily accessible by rovers, endoliths are afforded protection from surface conditions, and evidence of life could potentially be preserved through biomineralization and lithification. This study describes the bacterial communities from rock coatings compatible with martian mineralogy, explores the potential for biologically facilitated rock-coating formation, and supports rock coatings as targets of astrobiological interest on Mars.

Nutrient and population dynamics in a subglacial reservoir: a simulation case study of the Blood Falls ecosystem with implications for astrobiology

AbstractSubglacial ecosystems have recently become of interest within the astrobiological community, as they represent a potentially habitable location in otherwise uninhabitable environments. We used data from Blood Falls, particularly the periodic discharge from the subglacial reservoir beneath Taylor Glacier, Antarctica, to construct an ecosystem model of the putative subglacial microbial community residing there using system dynamics modelling. The model results were, for the most part, within an order of magnitude of the geochemical field data. Productivity was quite low, at 6.4×10−5g carbon l−1yr−1. Based on the results, we draw the following conjectures for the search for life on Mars: A similar ecosystem would require a continual supply of oxidized iron for energy and generate significant amounts of reduced iron as a waste product, be relatively resilient to temporary disturbances, and, thermodynamically, would require at least 0.003 kJ mol l−1of energy to survive at that level of productivity. These results may help to better identify the constraints and boundaries of ecosystems in extreme environments, on Earth and other planetary bodies.

Planetary Heating by Neutrinos: Long-Term Habitats for Aquatic Life if Dark Energy Decays Favourably

The potential cosmological and astrobiological implications of neutrinos are considered. Dark energy drives the current phase of accelerating cosmic expansion. Like inflation, it may decay in time to matter and radiation. However, since its energy density is minuscule in comparison, decay would be unlikely to inject such a rich variety of particles into the universe, and may instead be limited to the lowest energy fermions. Nonrelativistic neutrinos have the capacity to form stable, galaxy-engulfing haloes supported by degeneracy pressure, much like white dwarves and neutron stars. Conversely, bodies of mass can indefinitely rely on Coulomb forces for weight support. Opportunities for the mutual annihilation of electron neutrinos are largely confined to planets containing iron in the hcp phase. If dark energy decays primarily to neutrinos in 40 ~ 100 Gyr, then oceanic planets orbiting within the resulting haloes could provide long-term habitats for aquatic life with only lax constraints on the neutrino mass, . Various considerations now favour the possibility that neutrinos are Majorana particles with an inverted mass hierarchy and an electron neutrino mass in the vicinity of 50 meV. Sterile neutrinos of eV-mass may already be a significant component of dark matter, and could enhance planetary heating when active neutrino haloes become heavily depleted. An intriguing mechanism capable of regulating oceanic heat flux over a wide range of planetary masses is also described.

Astrobiological implications of chaos terrains on Europa to help targeting future missions

Reviewing the results from different authors on the ice crust and supposing the presence of an internal ocean inside Europa, chaos terrains and various lenticulae features might be in connection with submarine geothermal centers while pull-apart terrains and other linear features are probably in connection with tidal processes. Ranking the surface features according to the possibility how much are they connected to deep submarine processes, the above mentioned first group is more important than tidal related linear features.Surveying the size and height of blocks at the example terrain of Conamara Chaos we found that the thickness of the ice crust during its formation could be around 2km at the rafts and 0.5km at the matrix in agreement with some other authors’ estimated values. Calculating the hydrostatic pressure at the bottom of the approximately 25km thick ice crust 10 000–20 000kPa was estimated, and at the bottom of a 100km deep ocean at the order of 150 000kPa was found. At such pressure and assumed temperature, volcanic gases became dissolved in the water—although clathrates might also form, and could be released later as gas bubbles. This process was enhanced during the formation of chaos terrains if the ice crust thickness is only 2km at the active phase and the pressure is around 2400–3100kPa at its base, or inside a subsurface brine lens still roughly 100 times smaller than at the bottom of the ocean. Calthrate decomposition and bubble formation might be the most intensive at chaos regions and bubbles may be trapped between ice grains (McCord et al., 1999) or inside clathrate structure (Prieto-Ballesteros et al., 2004). Using terrestrial analog observations we conclude that trapped bubbles might be detectable remotely by the difference in the infrared and visual albedo, and by other scattering properties. The rationality of such observations is the highest at those units of the chaos regions’ low level matrix, where the smallest linear structures are present suggesting the strongest disruption, but they are not covered by debris aprons. The possibility of the detection of gas bubbles or other material floating upward in the warm rising plume is of high interest at chaos terrains, and development of detecting methods for the next Europa mission is useful.