Author: websterkgd

Hello Everyone,

The exciting news of the hour is that the carbon dioxide meter is now ready to be installed at Katchner Caverns.  The meter will be installed outside of the entrance of the cave to monitor changes in carbon dioxide in the atmosphere caused by cave breathing. In the figure below Dr. Wolfgang Fink is showing the custom battery pack we built for the meter and is pointing to a geologic map of Mars in the background. We plan to measure the composition of cave air near the entrance of Kartchner Caverns as a first step in measuring the composition of cave air on Mars.

Hi Everyone,

The free downloads associated with the links to my recently published articles in Astrobiology and Earth and Planetary Science Letters have expired. I have replaced those links to those of the articles. The links to those articles can also be found here.

– KW

Webster KD, Drobniak A, Etiope G, Mastalerz M, Sauer PE, Schimmelmann A (2017). Subterranean karst environments as a global sink for atmospheric methane. Earth and Planetary Science Letters, 485, 9-18. https://doi.org/10.1016/j.epsl.2017.12.025

Stelmach KB, Neveu M, Vick-Majors T, Mickol R, Chou L, Webster KD, Tilley M, Zacchei F, Escudero C, Flores Martinez C, Labrado A, Fernández E (2018). Secondary electrons as an energy source for life. Astrobiology, 18(1), 1-13. http://doi.org/10.1089/ast.2016.1510

An article is now out in Eos, the newspaper of the American Geophysical Union, that summarizes our observations of subatmospheric methane concentrations from caves across the world. Here is the link.

https://eos.org/articles/some-caves-remove-methane-from-the-atmosphere-new-tests-reveal

– Kevin

Hey Everyone,

The link below contains free access to my recent publication in Astrobiology. The link will be active until March 7th. Happy reading. – KW

http://bit.ly/2DBOmY5

As of March 7th 2015 the above link is defunct. You can view the article by following this link http://doi.org/10.1089/ast.2016.1510.

Hey Everyone,

Our article “Secondary electrons as an energy source for life” is now out in Astrobiology.

Abstract:

Life on Earth is found in a wide range of environments as long as the basic requirements of a liquid solvent, a nutrient source, and free energy are met. Previous hypotheses have speculated how extraterrestrial microbial life may function, among them that particle radiation might power living cells indirectly through radiolytic products. On Earth, so-called electrophilic organisms can harness electron flow from an extracellular cathode to build biomolecules. Here, we describe two hypothetical mechanisms, termed “direct electrophy” and “indirect electrophy” or “fluorosynthesis,” by which organisms could harness extracellular free electrons to synthesize organic matter, thus expanding the ensemble of potential habitats in which extraterrestrial organisms might be found in the Solar System and beyond. The first mechanism involves the direct flow of secondary electrons from particle radiation to a microbial cell to power the organism. The second involves the indirect utilization of impinging secondary electrons and a fluorescing molecule, either biotic or abiotic in origin, to drive photosynthesis. Both mechanisms involve the attenuation of an incoming particle’s energy to create low-energy secondary electrons. The validity of the hypotheses is assessed through simple calculations showing the biomass density attainable from the energy supplied. Also discussed are potential survival strategies that could be used by organisms living in possible habitats with a plentiful supply of secondary electrons, such as near the surface of an icy moon. While we acknowledge that the only definitive test for the hypothesis is to collect specimens, we also describe experiments or terrestrial observations that could support or nullify the hypotheses.

Recommended citation:

Stelmach KB, Neveu M, Vick-Majors T, Mickol R, Chou L, Webster KD, Tilley M, Zacchei F, Escudero C, Flores Martinez C, Labrado A, Fernández E (2018). Secondary electrons as an energy source for life. Astrobiology, 18(1), 1-13. http://doi.org/10.1089/ast.2016.1510