Results 91 to 100 of about 9,833 (194)

Taphonomy of biosignatures in carbonate nodules from the Mars-analog Qaidam Basin: constraints from microscopic, spectroscopic, and geochemical analyses

Frontiers in Astronomy and Space Sciences
Early diagenetic nodules with low permeable and weather-resistant structures are considered to be favorable for biosignature preservation. Numerous nodular structures forming in neutral-to-alkaline and saline diagenetic fluids were previously identified ...
Yan Chen, Zongjun Yin, Wei Lin
doaj   +1 more source

Metabolite changes in blood predict the onset of tuberculosis

, 2018
Immunogenetics and cellular immunology of bacterial infectious ...
Boom, W.H., Dockrell, H.M., Duffy, F.J., GC6-74 Consortium, Hanekom, W.A., Howe, R., Kaufmann, S.H.E., Maertzdorf, J., Mayanja-Kizza, H., McEwen, G., Mohney, R.P., Ottenhoff, T.H.M., Parida, S.K., Scriba, T.J., Suliman, S., Sutherland, J.S., Thiel, B., Thompson, E., Walzl, G., Weiner, J., Zak, D.E., Zyla, J.   +21 more
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Evaluating Biogenicity on the Geological Record With Synchrotron-Based Techniques

Frontiers in Microbiology, 2019
The biogenicity problem of geological materials is one of the most challenging ones in the field of paleo and astrobiology. As one goes deeper in time, the traces of life become feeble and ambiguous, blending with the surrounding geology.
Flavia Callefo, Lara Maldanis, Lara Maldanis, Verônica C. Teixeira, Rodrigo Adrián de Oliveira Abans, Rodrigo Adrián de Oliveira Abans, Thiago Monfredini, Fabio Rodrigues, Douglas Galante   +8 more
doaj   +1 more source

Inhabited or Uninhabited? Pitfalls in the Interpretation of Possible Chemical Signatures of Extraterrestrial Life

Frontiers in Microbiology, 2017
The “Rare Earth” hypothesis—put forward by Ward and Brownlee in their 2000 book of the same title—states that prokaryote-type organisms may be common in the universe but animals and higher plants are exceedingly rare.
Stefan Fox, Henry Strasdeit
doaj   +1 more source

Comparative Biosignatures

The discovery of inhabited exoplanets hinges on identifying biosignature gases. JWST is revealing potential biosignatures in exoplanet atmospheres, though their presence is yet to provide strong evidence for life. The central challenge is attribution: how to confidently identify biogenic sources while ruling out, or deeming unlikely, abiotic ...
Constantinou, Tereza, Shorttle, Oliver, Cranmer, Miles, Rimmer, Paul B.   +3 more
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Erratum: Correlation network analysis for amino acid identification in soil samples with the ORIGIN space-prototype instrument

Frontiers in Astronomy and Space Sciences, 2023
Frontiers Production Office
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Habitability and biosignatures

Preprint of a chapter for the 'Encyclopedia of Astrophysics' (Editor-in-Chief Ilya Mandel, Section Editor Dimitri Veras) to be published by Elsevier as a Reference ...
openaire   +2 more sources

Biosignature False Positives [PDF]

, 2018
In our search for life - whether within the earliest part of Earth's geologic record, on planets within our solar system such Mars, or especially for extrasolar planets - we must infer the presence of life from its impact on the local or global environment. These "biosignatures," often identified from the known influence of terrestrial organisms on the
Chester E. Harman, Shawn Domagal-Goldman
openaire   +1 more source

Extreme Forward Scattering Observed in Disk-averaged Near-infrared Phase Curves of Titan

The Planetary Science Journal
Titan, with its thick and hazy atmosphere, is a key world in our solar system for understanding light scattering processes. NASA’s Cassini mission monitored Titan between 2004 and 2017, where the derived data set includes a large number of whole disk ...
Chase Cooper, Tyler D. Robinson, Jason W. Barnes, L. C. Mayorga, Lily Robinthal   +4 more
doaj   +1 more source

An Objective Bayesian Analysis of Life's Early Start and Our Late Arrival

, 2020
Life emerged on the Earth within the first quintile of its habitable window, but a technological civilization did not blossom until its last. Efforts to infer the rate of abiogenesis, based on its early emergence, are frustrated by the selection effect ...
Kipping, David
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