490 Veritas

Description

With a diameter of more than 100 kilometers, Veritas is the largest member and namesake of the Veritas family, a mid-sized asteroid family of carbonaceous asteroids in the outer main-belt, that formed recently approximately 8.5±0.5 million years ago. David Nesvorný of the Southwest Research Institute in Boulder traced the orbits of these bodies back in time, and calculated that they formed in a collision of a body at least 150 km in diameter with a smaller asteroid. Veritas and Undina would have been the largest fragments of that collision which caused a "late Miocene dust shower". The family consists of more than a thousand known members including 1086 Nata, 2428 Kamenyar and 2934 Aristophanes.

Late Miocene dust shower

Substantiating Nesvorný's estimate, Kenneth Farley et al. found evidence in sea-floor sediments of a fourfold increase in the amount of cosmic dust reaching Earth's surface, which began 8.2 million years ago and tapered off over the next million and a half years. This is one of the largest increases in dust deposits of the past 100 million years.

The suspected Veritas collision would have been too far from Jupiter for the fragments to have been slung into a collision course with Earth. However, solar radiation would have caused the resulting dust to drift inward to Earth orbit over a time span consistent with the record of dust in the ocean sediment.

Today continuing collisions among Veritas-family asteroids are estimated to send five thousand tons of cosmic dust to Earth each year, 15% of the total.