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EON Workshop "Cosmic Perspective of Earth: A Planet Permeated and Shaped by Life - Implications for Astrobiology"

日付
September 13, 2017 - September 15, 2017
場所

ELSI Hall in ELSI-1 bldg., Tokyo Institute of Technology, Ookayama, Meguroku, Tokyo, Japan

Conveners:
Marjorie Chan - Professor, University of Utah
Jim Cleaves - EON Director, Earth-Life Science Institute
Penelope Boston -Director, NASA Astrobiology Institute (NAI)

Please refer to the EON official website (link below)
http://eon.elsi.jp/cosmic-perspective-of-earth-a-planet-permeated-and-shaped-by-life-implications-for-astrobiology/

Pervasive Life Perspective
Life permeates Earth's surface. All of Earth's surface water, and probably its subsurface fluid, has been "contaminated" with microbes since at least 3.5 Ga. Given the vast time that Earth has been teeming with life, do we even know what an "abiotic habitable planet" looks like?

Scientists now recognize the strong interdependent linkages of biology, chemistry, and geology- giving rise to the disciplines of geomicrobiology and astrobiology. To determine whether life exists elsewhere in the Universe, it will be necessary to define what constitutes a biosignature or a biomarker, and how extant life would be preserved (taphonomy) and recognized. Researchers have focused on Earth's critical zone - the near surface environment of complex interactions between rock, soil, air, water, and life. We generally assume every organic compound, mineral assemblage and texture is abiotic unless we can definitively show a biotic influence. However, how would our research questions change if we assume that all we see on Earth is biotic unless we can prove it is abiotic?

Our workshop hypothesis is: Everything on Earth influenced by water is inseparably coupled with life. We do not really know what "abiotic" environments look like on the Earth's surface. How can we best test and evaluate abiotic conditions? Do we know what the limits and boundaries of life are? The astonishing resilience of extremophiles suggests that life might extend beyond the currently known limits, i.e., there are "long tails" of life outside of the norms.

Workshop participants from a wide range of disciplines are invited to bring their expertise to address this hypothesis and the difficulties that an Earth-based bias of evaluating biomarkers brings to astrobiology exploration.