Impact events

How Much Water Was Delivered From The Asteroid Belt To The Earth After Its Formation?

By Keith Cowing
June 9, 2021
Filed under
How Much Water Was Delivered From The Asteroid Belt To The Earth After Its Formation?
Asteroid bombardment

The Earth contains between one and ten oceans of water, including water within the mantle, where one ocean is the mass of water on the Earth’s surface today. With n-body simulations we consider how much water could have been delivered from the asteroid belt to the Earth after its formation.

Asteroids are delivered from unstable regions near resonances with the giant planets. We compare the relative impact efficiencies from the ν6 resonance, the 2:1 mean motion resonance with Jupiter and the outer asteroid belt. The ν6 resonance provides the largest supply of asteroids to the Earth, with about 2% of asteroids from that region colliding with the Earth. Asteroids located in mean motion resonances with Jupiter and in the outer asteroid belt have negligible Earth-collision probabilities.

The maximum number of Earth collisions occurs if the asteroids in the primordial asteroid belt are first moved into the ν6 resonance location (through asteroid-asteroid interactions or otherwise) before their eccentricity is excited sufficiently for Earth collision. A maximum of about eight oceans of water may be delivered to the Earth. Thus, if the Earth contains ten or more oceans of water, the Earth likely formed with a significant fraction of this water.

Rebecca G. Martin, Mario Livio

Comments: Accepted for publication in MNRAS Letters
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2106.03999 [astro-ph.EP] (or arXiv:2106.03999v1 [astro-ph.EP] for this version)
Submission history
From: Rebecca Martin
[v1] Mon, 7 Jun 2021 22:46:47 UTC (243 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻