Scientists have made a discovery on asteroid Bennu. They found parts of another asteroid on Bennu's surface. They're now figuring out how this happened.
The chunks are from asteroid Vesta.They were discovered by NASA's OSIRIS-REx asteroid probe. This vehicle has been orbiting Bennu for months now. Currently, it's testing its ability to collect samples from the large space rock.
Bennu was discovered on the 11th of September 1999. The asteroid is listed in the Sentry Risk Table. It has a mean diameter of 490 m.
The OSIRIS-REx mission intends to bring samples to Earth in 2023. The OSIRIS-Rex asteroid probe arrived at Bennu on 3 December 2018. The vehicle's journey took two-years. The probe is currently mapping out the surface of the rock.
The OSIRIS-REx spacecraft has also captured images of Bennu's surface. Some of the images were taken at a distance of 600 meters. Scientists at NASA believe Bennu was formed after a massive collision. The remaining material from the collision was collected into a ball. It then drew more debris due to gravity. The asteroid's surface is filled with dirty debris.
Asteroid Vesta is in the asteroid belt between Mars and Jupiter. Some of its parts have fallen to Earth. Scientists found chunks of Vesta on Bennu's surface. They're now trying to find out how this happened.
The leading theory points to inherited material from parent asteroid. This happened after a fragment of Vesta hit the parent. Portions of this debris accumulated into Bennu. Gravity played a big role in this process. Scientists identified six boulders on Bennu's southern hemisphere. These boulders have different sizes ranging from 5 to 14 feet. Images show that these boulders are much brighter and they match material from the Vesta asteroid. This supports the hypothesis that Bennu inherited the material from a parent asteroid. The material then accumulated to form Bennu.
Asteroid Bennu's Composition
The boulders are composed of pyroxene minerals. Scientists identified the pyroxene using a spectrometer. Pyroxene forms when rocky material melts at high-temperatures. However, Bennu is made of water-bearing rocks. This material might have been inherited from asteroids with pyroxene minerals. However, this is not unusual.
Asteroids can have materials from other asteroids. Asteroids move around the solar system. However, their orbits can be altered. This is caused by meteoroid impacts or gravity from planets. This results in a complex formation process.
Bennu was initially in the inner region of the Main Asteroid Belt. It then moved to near-Earth orbits. This movement was caused by a gravitational pathway. The asteroid probe will attempt to collect samples in October. It will then bring them to Earth in 2023. Scientists have identified four sample sites on Bennu. Once the samples are collected they'll then be analyzed. This will provide scientific and safety value.
NASA researchers are working hard on this daring mission. More discoveries will be made if the probe returns the samples. Scientists will learn more about the origin of these rocks. It will also shed light on how Bennu was formed.