Jupiter in the Solar System for which this is true. Jupiter has been called the Solar System's vacuum cleaner, because of its immense gravity well and location near the inner Solar System. It receives the most frequent comet impacts of the Solar System's planets. It was thought that the planet served to partially shield the inner system from cometary bombardment. However, recent computer simulations suggest that Jupiter does not cause a net decrease in the number of comets that pass through the inner Solar System, as its gravity perturbs their orbits inward roughly as often as it accretes or ejects them.
Planet V Sun after entering the ν secular resonance. As an initial test of the Planet V hypothesis, Chambers and Lissauer conducted 36 computer simulations of the Solar System with an additional terrestrial planet. A variety of parameters were used to determine the impacts of Planet V's initial orbit and mass. The mean time at which Planet V was lost was found to increase from 100 Myr to 400 Myr as its initial semi-major axis was increased from 1.8 to 1.9 AU. Results consistent with the current Solar System were most common with a 0.25 Mars mass Planet V. In cases with