Presence of water on exomoons orbiting free-floating planets: a case study

Abstract

A free-floating planet is a planetary-mass object that orbits around a non-stellar massive object (e.g. a brown dwarf) or around the Galactic Center. The presence of exomoons orbiting free-floating planets has been theoretically predicted by several models. Under specific conditions, these moons are able to retain an atmosphere capable of ensuring the long-term thermal stability of liquid water on their surface. We model this environment with a one-dimensional radiative-convective code coupled to a gas-phase chemical network including cosmic rays and ion-neutral reactions. We find that, under specific conditions and assuming stable orbital parameters over time, liquid water can be formed on the surface of the exomoon. The final amount of water for an Earth-mass exomonoon is smaller than the amount of water in Earth oceans, but enough to host the potential development of primordial life. The chemical equilibrium time-scale is controlled by cosmic rays, the main ionization driver in our model of the exomoon atmosphere.

12 pages, 6 figures

References in corpus (15)

• On the radiative equilibrium of irradiated planetary atmospheres
• The 2014 KIDA network for interstellar chemistry
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• VULCAN: an Open-Source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres
• Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun
• On the Absorption and Redistribution of Energy in Irradiated Planets
• Formation, Habitability, and Detection of Extrasolar Moons
• HEK VI: On the Dearth of Galilean Analogs in Kepler and the Exomoon Candidate Kepler-1625b I
• An Analytic Radiative-Convective Model for Planetary Atmospheres
• No Evidence for Lunar Transit in New Analysis of Hubble Space Telescope Observations of the Kepler-1625 System
• An alternative interpretation of the exomoon candidate signal in the combined Kepler and Hubble data of Kepler-1625
• The Survival Rate of Ejected Terrestrial Planets with Moons
• The Demographics of Rocky Free-Floating Planets and their Detectability by WFIRST
• Innocent Bystanders: Orbital Dynamics of Exomoons during Planet-Planet Scattering
• Origin and Stability of Exomoon Atmospheres - Implications for Habitability

Cited by in corpus (8)

• On the Detection of Exomoons Transiting Isolated Planetary-Mass Objects
• Potential long-term habitable conditions on planets with primordial H-He atmospheres
• Microlensing due to free-floating moon-planet systems
• Presence of liquid water during the evolution of exomoons orbiting ejected free-floating planets
• On the Stability of Additional Moons Orbiting Kepler-1625 b
• Chasing Nomadic Worlds: A New Class of Deep Space Missions
• The Fermi paradox: Impact of astrophysical processes and dynamical evolution
• Life in the dark: Potential urability of moons of rogue planets