Unlabelled: The oxidation of molecular hydrogen (H2) is thought to be a major source of metabolic energy for life in the deep subsurface on Earth, and it could likewise support any extant biosphere on Mars, where stable habitable environments are probably limited to the subsurface. Faulting and fracturing may stimulate the supply of H2 from several sources. We report the H2 content of fluids present in terrestrial rocks formed by brittle fracturing on fault planes (pseudotachylites and cataclasites), along with protolith control samples. The fluids are dominated by water and include H2 at abundances sufficient to support hydrogenotrophic microorganisms, with strong H2 enrichments in the pseudotachylites compared to the controls. Weaker and less consistent H2 enrichments are observed in the cataclasites, which represent less intense seismic friction than the pseudotachylites. The enrichments agree quantitatively with previous experimental measurements of frictionally driven H2 formation during rock fracturing. We find that conservative estimates of current martian global seismicity predict episodic H2 generation by Marsquakes in quantities useful to hydrogenotrophs over a range of scales and recurrence times. On both Earth and Mars, secondary release of H2 may also accompany the breakdown of ancient fault rocks, which are particularly abundant in the pervasively fractured martian crust. This study strengthens the case for the astrobiological investigation of ancient martian fracture systems.
Key Words: Deep biosphere-Faults-Fault rocks-Seismic activity-Hydrogen-Mars. Astrobiology 16, 690-702.
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http://dx.doi.org/10.1089/ast.2015.1405 | DOI Listing |
Sensors (Basel)
December 2024
Electrical, Computer, and Biomedical Engineering, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada.
Autonomous technologies have revolutionized transportation, military operations, and space exploration, necessitating precise localization in environments where traditional GPS-based systems are unreliable or unavailable. While widespread for outdoor localization, GPS systems face limitations in obstructed environments such as dense urban areas, forests, and indoor spaces. Moreover, GPS reliance introduces vulnerabilities to signal disruptions, which can lead to significant operational failures.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Division of Space, Ecological, Arctic, and Resource-limited (SPEAR) Medicine, Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA 02114.
One of the most surprising and important findings of the first human landings on the Moon was the discovery of a very fine layer of lunar dust covering the entire surface of Moon along with the negative impacts of this dust on the well-being and operational effectiveness of the astronauts, their equipment, and instrumentation. The United States is now planning for human missions to Mars, a planet where dust can also be expected to be ubiquitous for many or most landing sites. For these missions, the design and operations of key hardware systems must take this dust into account, especially when related to crew health and safety.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Division of Earth and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125.
Mars Sample Return (MSR) has been the highest flagship mission priority in the last two Planetary Decadal Surveys of the National Academies of Science, Engineering, and Medicine (hereafter, "the National Academies") and was the highest priority flagship for Mars in the Decadal Survey that preceded them. This inspirational and challenging campaign, like the Apollo program's returned lunar samples, will potentially revolutionize our understanding of Mars and help inform how other planets are explored. MSR's technological advances will keep the NASA and European Space Agency at the forefront of planetary exploration, and data on returned samples will fill knowledge gaps for future human exploration.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany.
The search for evidence of past prebiotic or biotic activity on Mars will be enhanced by the return of samples to Earth laboratories. While impressive analytical feats have been accomplished by in situ missions on the red planet, accessing the capabilities of Earth's global laboratories will present a step change in data acquisition. Highly diagnostic markers of past life are biomarkers, organic molecules whose architecture can be attributed to once living organisms.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109.
The NASA Mars 2020 Perseverance Rover Mission has collected samples of rock, regolith, and atmosphere within the Noachian-aged Jezero Crater, once the site of a delta-lake system with a high potential for habitability and biosignature preservation. Between sols 109 and 1,088 of the mission, 27 sample tubes have been sealed, including witness tubes. Each sealed sample tube has been collected along with detailed documentation provided by the Perseverance instrument payload, preserving geological and environmental context.
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