Britannica Sources used in this answer

Why do asteroid collisions create meteoroids and interplanetary dust?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Meteor and meteoroid The Cabin Creek meteorite, an iron (nickel-iron alloy) meteorite that was observed to fall in northwestern Arkansas on March 27, 1886. Its characteristic pattern of “thumbprint” dimples, or regmaglypts, is the result of melting and consequent ablation of its surface as it traveled through the atmosphere. The meteorite is likely a fragment of one of the M class asteroids, which show significant nickel-iron in their surface material.

Asteroid collisions are a fundamental "grinding process" that shapes the population of the asteroid belt. Because these bodies possess significant orbital eccentricities and inclinations, they frequently collide with one another at high velocities, averaging about 5 km per second.1

These impacts cause the fragmentation of larger asteroids, breaking them down into smaller pieces. This continuous collisional evolution results in a size distribution that extends from large asteroids down to smaller meteoroidal bodies and eventually to fine interplanetary dust.12

In essence, meteoroids are the debris produced by the destruction of larger asteroids, while the smallest particles—interplanetary dust—are the result of this same ongoing pulverization. While collisions are the primary source of this material, the resulting fragments are then transported toward Earth through mechanisms such as gravitational resonances with Jupiter or, in the case of fine dust, through Poynting-Robertson drag, which causes particles to spiral inward toward the inner solar system.1