NASA has revealed that an asteroid named Bennu could pose a threat to Earth in the next two centuries. The space agency has been studying the near-Earth asteroid with its OSIRIS-REx mission, which collected a sample from its surface last year. The mission has improved the understanding of Bennu’s orbit and its potential impact scenarios.
Bennu’s impact probability
Bennu is one of the most hazardous asteroids in our solar system, as it has a 1 in 1,750 chance of impacting Earth through 2300, according to a new study published in the journal Icarus. This is higher than the previous estimate of 1 in 2,700, based on less precise data. The study used the observations from OSIRIS-REx and other sources to refine Bennu’s orbit and reduce the uncertainties about its future trajectory.
The most likely date for an impact is September 24, 2182, with a probability of 0.037%. However, this does not mean that Bennu will definitely hit Earth on that day, as there are many factors that could alter its course, such as the gravitational pull of other planets and the Yarkovsky effect, which is the change in an asteroid’s orbit due to the uneven heating and cooling of its surface.
Bennu’s characteristics and origins
Bennu is a carbon-rich asteroid that measures about one-third of a mile (0.5 kilometers) across, roughly the height of the Empire State Building. It orbits the sun every 14 months and rotates every four hours. It is believed to be a remnant of a larger asteroid that broke apart in a collision with another space rock.
Scientists are interested in Bennu because it could hold clues to the formation of our solar system and the origin of life on Earth. Bennu is thought to contain organic molecules and water-bearing minerals that date back to 4.5 billion years ago, when the solar system was young. By analyzing the sample collected by OSIRIS-REx, which is expected to land in Utah on Sunday, researchers hope to learn more about these ancient materials and their potential for supporting life.
NASA’s planetary defense efforts
NASA’s OSIRIS-REx mission is part of its planetary defense program, which aims to find and monitor asteroids and comets that can come near Earth and pose a hazard to our planet. The mission has provided an unprecedented opportunity to test and refine the models that predict the impact risk of near-Earth objects.
In addition to studying Bennu, NASA is also preparing for another mission called DART (Double Asteroid Redirection Test), which will attempt to deflect an asteroid by crashing into it. The target is a moonlet named Dimorphos, which orbits a larger asteroid called Didymos. The mission will launch later this year and reach its destination in 2022.
By conducting these missions, NASA hopes to improve its capabilities and knowledge for preventing or mitigating potential asteroid impacts in the future.