2008/12/24 by Jonathan Horner, Jonti Horner, Barrie W. Jones +1 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Planetary Science and Exploration #Stellar, planetary, and galactic studies #astro-ph.EP
paper · pdf · doi:10.1017/s1473550408004357
13 pages, 1 Figure
openalex publication_date 2008/12/24 · arxiv created 2009/03/19 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of minor bodies upon the Earth, and thus enabling the development and evolution of life in a collisional environment which is not overly hostile. However, in the past, little work has been carried out to examine the validity of this idea. In the second of a series of papers, we examine the degree to which the impact risk resulting from objects on Centaur-like orbits is affected by the presence of a giant planet, in a continuing attempt to fully understand the impact regime under which life on Earth has developed. The Centaurs, which occupy orbits beyond Jupiter, have their origins in the Edgeworth-Kuiper belt that extends beyond Neptune. The giant planets peturb the Centaurs, sending a significanr fraction into the inner Solar System where they become visible as short-period comets. In this work we present results which show that the presence of a giant planet can act to significantly change the impact rate of short-period comets on the Earth, and that a giant planet often actually increases the impact flux greatly over that which would be expected were it not present. (Shortened version of abstract.)