Planetary magnetism as a parameter in exoplanet habitability
Abstract
Evidence from the Solar system suggests that, unlike Venus and Mars, the presence of a strong magnetic dipole moment on Earth has helped maintain liquid water on its surface. Therefore, planetary magnetism could have a significant effect on the long-term maintenance of atmosphere and liquid water on rocky exoplanets. We use Olson & Christensen's (2006) model to estimate magnetic dipole moments of rocky exoplanets with radii Rp ≤ 1.23 R⊕. Even when modelling maximum magnetic dipole moments, only Kepler-186 f has a magnetic dipole moment larger than the Earth's, while approximately half of rocky exoplanets detected in the circumstellar habitable zone have a negligible magnetic dipole moment. This suggests that planetary magnetism is an important factor when prioritizing observations of potentially habitable planets.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2019
- DOI:
- 10.1093/mnras/stz667
- arXiv:
- arXiv:1903.03123
- Bibcode:
- 2019MNRAS.485.3999M
- Keywords:
-
- planets and satellites: general;
- planets and satellites: magnetic fields;
- planets and satellites: terrestrial planets;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for publication in MNRAS, 14 pages, 4 figures