How did asteroid formed? This is a mystery since decades.
But a newly discovered asteroid group, the dark asteroids, could show how the objects formed. Planetesimals had to be huge, and this family was one of the biggest.
The formation of asteroids isn’t clear yet. Now, the discovery of a family of “dark” asteroids gives hints on how the objects formed.
By aggregating the sizes of the modern dark asteroids, researchers suggest the original dark planetesimals formed about 4 billion years ago, making this one of the oldest asteroid families in the main belt.
Moreover, it seems that the dark family’s original planetesimals were huge and that their diameters were no smaller than 35 kilometers across. That’s corroborating the gravitational collapse theory of asteroid formation, which states that asteroids had to be huge.
And this new asteroid family was one of the biggest.