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NASA NTRS · 20040173047

Habitable moons around extrasolar giant planets

Williams, D. M.·Kasting, J. F.·Wade, R. A.
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Abstract

Possible planetary objects have now been discovered orbiting nine different main-sequence stars. These companion objects (some of which might actually be brown dwarfs) all have a mass at least half that of Jupiter, and are therefore unlikely to be hospitable to Earth-like life: jovian planets and brown dwarfs support neither a solid nor a liquid surface near which organisms might dwell. Here we argue that rocky moons orbiting these companions could be habitable if the planet-moon system orbits the parent star within the so-called 'habitable zone', where life-supporting liquid water could be present. The companions to the stars 16 Cygni B and 47 Ursae Majoris might satisfy this criterion. Such a moon would, however, need to be large enough (>0.12 Earth masses) to retain a substantial and long-lived atmosphere, and would also need to possess a strong magnetic field in order to prevent its atmosphere from being sputtered away by the constant bombardment of energetic ions from the planet's magnetosphere.

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NASA Discipline ExobiologyNon-NASA CenterExobiologyPlanetsSupport, U.S. Gov't, Non-P.H.SWaterExtraterrestrial Environment

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Williams, D. M., Kasting, J. F., Wade, R. A.. 1997-01-16. Habitable moons around extrasolar giant planets. https://ntrs.nasa.gov/citations/20040173047

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