NASA focuses its attention on the Bennu asteroid, as the space agency studies it with the OSIRIS-REx spacecraft. The probe was sent in 2018 towards the asteroid, with the initial goal of bringing back to Earth small samples in order to examine the composition. But as it usually happens, scientists got interested in something more.
The Bennu asteroid has been observed to shoot tiny chunks of rock into space, at more than a year after the OSIRIS-REx spacecraft began to study it. A collection of studies from the Journal of Geophysical Research: Planets comes to shed some light on why the unusual activity of the bouncing particles occurs at Bennu’s surface.
Active as a comet
As a comet’s ice gets heated by the sun, the material gets evaporated in space. Surprisingly enough, the Bennu asteroid could behave in pretty much the same way as a comet.
YouTube channel JPLraw presents a relevant animation:
“Using data collected by NASA’s OSIRIS-REx mission, this animation shows the trajectories of rock particles after being ejected from asteroid (101955) Bennu’s surface.”
Steve Chesley from NASA’s Jet Propulsion Laboratory in Southern California and his colleagues came to provide an explanation for what is causing the launch of the asteroid’s particles. The culprit could be a combination of the asteroid’s heat and cooling during rotation together with tiny rocks that hit its surface during the orbit around the sun.
The Apollo group is the location of the Bennu asteroid, and the space rock has a diameter of 490 m. Bennu was discovered by the LINEAR Project more than two decades ago: in September 1999. The asteroid is classified as a potentially hazardous object. Although it’s dangerously big, there’s no need to worry that Bennu will collide with Earth. The asteroid has a cumulative 1-in-2,700 chance of hitting our planet between 2175 and 2199. And we hate to disappoint you, but none of us will be living in those times.
The asteroid was named after Bennu, a mythological figure from Egypt – Bennu was the bird that was associated with creation, the sun, and rebirth.