OSIRIS-REx spacecraft spots particles ejected from asteroid and selects landing spot - Astronomy and space – Physics World13 Dec 2019, 15:32 UTC
Images gathered by NASA’s OSIRIS-REx mission to the near-Earth asteroid 101955 Bennu show the asteroid ejecting small amounts of material in three distinct events. The observation was made by an international team of astronomers led by Dante Lauretta at the University of Arizona, who believe that it suggests that all similar asteroids may be at least partially active. If correct, this insight could improve our understanding of the evolution of asteroids, and the origins of interplanetary dust.
The OSIRIS-Rex team has also decided that the spacecraft will land at a site on Bennu called “Nightingale”, which is located in a crater high in the asteroid ’s northern hemisphere. There, the spacecraft will obtain a soil sample before taking-off in 2021 for a scheduled return to Earth in 2023. The site was chosen from four perspective locations on the asteroid because it appears to be devoid of large rocks and boulders. It is, however, only about 140 m wide, so NASA scientists must be careful not to set the spacecraft down onto one of the large boulders just outside the perimeter of Nightingale.
Made of boulders
Bennu is a roughly spherical asteroid around 500 m in diameter that circles the Sun ...