Alien Worlds On Earth?
Amidst 70 quintillion planets in the cosmos, does Earth truly stand alone as the sole source of life? In a pioneering partnership with the National Aeronautics and Space Administration, we've unearthed thriving microscopic communities beneath Antarctica's ice sheets, offering a glimpse into life's potential existence on distant, oxygen-starved oceanic worlds.
Biological methane production may be possible on extraterrestrial ocean worlds such as Enceladus, the sixth largest moon of Saturn. We studied the chemosynthetic pathways used by life in the isolated, perennially ice-covered Antarctic Lake Untersee - an analog to such an extreme environment - for the 2019 American Geophysical Union Fall Meeting. We analyzed water and benthic sediment samples from Untersee, whose light-starved, near-freezing anoxic zone is one of the most methane-rich aquatic ecosystems on Earth.
The presence of methane in this lake, where no seepage occurs, suggests a biological origin; our bioinformatic analysis of these samples, which revealed the presence of methanogenic archaea and the complete methanogenesis pathway, supports this conclusion. As the conditions under which these organisms and metabolisms are thriving could exist on extraterrestrial worlds, our findings have far-reaching implications for the search for life beyond the confines of Earth.
Read more here: https://ui.adsabs.harvard.edu/abs/2019AGUFM.P24A..04W/abstract
