Life Around M-Stars

M-Star Habitability

by Peter R. BackusJill C. Tarter, and Rocco L. Mancinelli

Traditionally, consideration of life beyond the Solar System has been limited to “solar-type” stars. Low mass stars, spectral type M, are far more numerous. If they are viable hosts for habitable worlds, the number of potential life sites in the galaxy increases by up to a factor of eight. To determine whether M stars should be included in future astrobiology research, our team convened the first in a series of workshops in July 2005. A total of 30 scientists, including 13 from 7 NAI teams, reconsidered the issue of habitable planets orbiting M stars from diverse points of view: planet formation, planetary environment, origin of life, and the evolution of complexity. The conclusion of the first workshop is that at least some M dwarf stars deserve further consideration.

m-stars
Life Around M-Stars. Image credit: Lynette Cook

The ultimate results of the workshops will influence many areas of research, such as studies of extremophiles and predicting biosignatures for habitable planets orbiting M dwarf stars. Our own SETI (Search for Extraterrestrial Intelligence) program will use the results to build a list of more than a million stars that will be searched for evidence of intelligent, technological life. Such a large list is needed to best take advantage of a new advanced radio telescope, the Allen Telescope Array, a joint effort of the SETI Institute and UC Berkeley.

Project Progress: We held a two and a half day workshop on July 18-20, 2005 on the topic of the Habitability of Planets Orbiting M Stars. Thirty scientists from nineteen institutions in the US and UK participated.  Thirteen of the participants were from six other NAI Teams.  Results of the workshop are reported in a paper submitted to the journal Astrobiology.  The paper was written over many months through the use of email lists and a secure private web site.  Another web site provided information for the general public.  (2006 NAI Annual Report)workshop photo

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