What causes the formation of Kirkwood Gaps?

The formation of Kirkwood Gaps is primarily attributed to orbital resonance with Jupiter. These gaps are created in the distribution of asteroids in the asteroid belt, where the gravitational influence of Jupiter causes certain regions to be less populated with asteroids.

When asteroids have an orbital period that is a simple fraction of Jupiter’s orbital period, they can experience gravitational perturbations that either lead them to be ejected from those regions or prevent new asteroids from settling into those orbits. For instance, asteroids that resonate with Jupiter's orbit can either gain energy and be sent inward toward the Sun or lose energy and be sent outward into different orbits, leading to a scarcity of asteroids in those specific regions, which manifests as gaps.

This dynamic interaction between Jupiter and the surrounding asteroids effectively keeps some areas devoid of significant asteroid presence, resulting in the distinct Kirkwood Gaps we observe today.