Open AccessLatitude Variation of Flux and Impact Angle of Asteroid Collisions with Earth and the Moon
Author(s) -
Darrel Robertson,
Petr Pokorný,
Mikael Granvik,
Lorien Wheeler,
Clemens Rumpf
Publication year - 2021
Publication title -
the planetary science journal
Language(s) - English
Resource type - Journals
ISSN - 2632-3338
DOI - 10.3847/psj/abefda
Subject(s) - equator , flux (metallurgy) , precession , asteroid , latitude , variation (astronomy) , collision , population , physics , geology , geodesy , environmental science , atmospheric sciences , astrobiology , astrophysics , astronomy , demography , materials science , computer security , sociology , computer science , metallurgy
Flux and impact angles were calculated for asteroid collisions with Earth and the Moon, using the latest population models for the distribution of near-Earth objects (NEOs) and precession models to determine the impact probabilities. The calculations predict that the flux of impacts to the poles for Earth is 22% greater than the flux at the equator, and 55% greater for the Moon. Impacts near the equator typically have shallower impact angles with a mode near 30° above the horizontal. Conversely, impacts near the poles are typically steep with a mode close to 65°. Our new analysis updates the previously published results by Le Feuvre & Wieczorek incorporating: (1) an updated debiased distribution of NEOs, and (2) updated collision probabilities that account for Lidov–Kozai precession. The new impact distributions provide an important update to risk models, showing a 7% increase in average population risks from sub-300 m impactors, compared to previous atmospheric entry distributions, mostly due to faster impact velocities.