MIT Scientists Compile List of Potential Gases to Guide Search for Life on Exoplanets
New Rochelle, May 5, 2016—A new approach intended to maximize the chances of identifying planets orbiting nearby stars that support life focuses on creating a comprehensive list of the molecules that might be present in the atmospheres of these exoplanets. Biosignature gases emitted by exoplanetary life forms could be detected remotely by space telescopes, but these gases might have quite different compositions from those in Earth’s atmosphere, according to an article in Astrobiology, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free for download on the Astrobiology website until June 5, 2016.
S. Seager, W. Bains, and J.J. Petkowski, MIT (Cambridge, MA) and Rufus Scientific (Cambridge, U.K.), propose that all stable and potential volatile molecules should be considered as possible biosignature gases. In the article “Toward a List of Molecules as Potential Biosignature Gases for the Search for Life on Exoplanets and Applications to Terrestrial Biochemistry,” the researchers laid the groundwork for identifying such gases by conducting a massive search for molecules with six or fewer non-hydrogen atoms. They describe how this exhaustive list of small molecules can help enhance our understanding of the limits of biochemistry on Earth.
“This work reminds me of Darwin’s voyage aboard The Beagle, exploring the vast diversity of life by sailing around the world,” says Nancy Y. Kiang, PhD, Senior Editor of Astrobiology and a scientist at NASA Goddard Institute for Space Studies. “In the search for life beyond our planet, we are currently at a similarly exciting, early but rapidly evolving stage of exploration as the discovery of exoplanets accelerates. Instead of netting strange creatures from the bottom of the sea, the authors here have searched and found thousands of curious, potentially biogenic gas molecules. These will inspire a new body of research into identifying also larger molecules, investigating their origin and fate here, and their potential expression on exoplanets as signs of life.”
The hunt for life beyond the Solar System is gaining new partners: NASA climatologists. After more than 30 years of studying Earth, a team at the NASA Goddard Institute for Space Studies (GISS) in New York will adapt its global climate model to simulate conditions on potentially habitable exoplanets. The effort is part of a broader push to identify Earth-like worlds that NASA will launch on 20 April at a meeting in Washington DC.
Already, the agency’s space-based Kepler telescope has pinpointed more than 1,000 alien planets by observing the brief interruption of starlight that signals a planet passing in front of its parent star. At least five of these planets are similar in size to Earth and located in the ‘habitable zone’, where liquid water could persist. The next step would be to detect light passing through exoplanet atmospheres, which could hold clues to conditions on these distant worlds.