An asteroid just slightly wider than the Empire State Building has confused many scientists by shooting out plumes of dust, as shown by a new set of close-up images from NASA. Bennu is the near-Earth asteroid that NASA’s OSIRIS-REx mission has been observing since December 31st last year, and is already confounding scientists in a variety of ways.
Asteroids that shoot particles are very rare. What is more rare is the chances of a particle-spewing asteroid being one that NASA picked for observation. This means that Bennu is actually an active asteroid, of which only a dozen have been found among the nearly 800,000 that the scientists have observed.
Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson, said that the discovery of plumes is one of the biggest surprises of his scientific career.
On January 6th, OSIRIS-REx scientists discovered the first particle explosion on Bennu’s surface. A dozen more would probably come in the next couple of months. After deciding that the particles would not pose any risk to the spacecraft, the mission team had decided to track them in order to analyze their potential causes. The team is still in the process of finding exploding particles.