NASA sent the OSIRIS-REx probe for orbiting around the 101955 Bennu asteroid (commonly known simply as Bennu), and several months of exploration had already passed. The asteroid is classified as a potentially hazardous object, and it features a diameter of about 490 meters.
After so much time of studying the asteroid’s surface, NASA’s probe discovers something intriguing: Bennu has parts of another asteroid scattered on its surface.
The discovery provides a better understanding of asteroids’ formation
It’s a mystery for how those asteroid parts arrived on Bennu. Some scientists believe that Bennu represents the outcome of a collision between two objects. The material leftover gathered together and then drew more and more debris due to the effects of gravity.
Hannah Kaplan from NASA’s Goddard Space Flight Center declared:
Our leading hypothesis is that Bennu inherited this material from its parent asteroid after a vestoid (a fragment from Vesta) struck the parent,
Then, when the parent asteroid was catastrophically disrupted, a portion of its debris accumulated under its own gravity into Bennu, including some of the pyroxene from Vesta.
NASA also informs the public that it’s not something unusual for an asteroid to have material belonging from another one scattered across its surface. The agency explains:
Examples include dark material on crater walls seen by the Dawn spacecraft at Vesta, a black boulder seen by the Hayabusa spacecraft on Itokawa, and very recently, material from S-type asteroids observed by Hayabusa2 at Ryugu.
The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a sample-return mission that aims to obtain a sample of a minimum of 60 grams (2.1 oz) from the Bennu asteroid.
The Bennu asteroid has a cumulative 1-in-2,700 chance of hitting Earth between 2175 and 2199. The asteroid is named after Bennu, the ancient Egyptian mythological bird that was associated with the Sun, creation, and rebirth.
