Jupiter - friend or foe? III: the Oort cloud comets

TL;DR

This study investigates how a Jupiter-like planet influences the impact rate of Oort cloud comets on Earth, revealing that larger planetary mass reduces impact frequency, challenging the traditional view of Jupiter as a protective shield.

Contribution

It provides new insights into the impact regime influenced by a giant planet's mass and orbit, specifically regarding Oort cloud comets and Earth's impact history.

Findings

Impact rate decreases as the giant planet's mass increases.

Greatest impact flux occurs without a giant planet present.

Presence of a Jupiter-like planet significantly alters impact frequency.

Abstract

It has long been assumed that the planet Jupiter acts as a giant shield, significantly lowering the impact rate of small bodies on the Earth. However, until recently, very little work had been carried out examining the role played by Jupiter in determining the frequency of such collisions. In this work, the third of a series of papers, we examine the degree to which the impact rate on Earth resulting from the Oort cloud comets is enhanced or lessened by the presence of a giant planet in a Jupiter-like orbit, in an attempt to more fully understand the impact regime under which life on Earth has developed. Our results show that the presence of a giant planet in a Jupiter-like orbit significantly alters the impact rate of Oort cloud comets on the Earth, decreasing the rate as the mass of the giant increases. The greatest bombardment flus is observed when no giant planet is present.