Planetary Magnetism as a Parameter in Exoplanet Habitability

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 and 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.

Sarah R.N. McIntyre, Charles H. Lineweaver, Michael J. Ireland
(Submitted on 7 Mar 2019)

Comments: Accepted for publication in MNRAS, 14 pages, 4 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
DOI: 10.1093/mnras/stz667
Cite as: arXiv:1903.03123 [astro-ph.EP] (or arXiv:1903.03123v1 [astro-ph.EP] for this version)
Submission history
From: Sarah McIntyre
[v1] Thu, 7 Mar 2019 19:01:21 UTC (1,104 KB)
https://arxiv.org/abs/1903.03123
Astrobiology