NASA just increased the probability of Bennu striking Earth in the next century or two from 1-in-2700 to 1-in-1750. Bennu is a carbonaceous near-earth asteroid – about the size of a skyscraper and some 200 million miles from Earth.
On September 8, 2019, NASA launched OSIRIS-Rex (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) to study and obtain at least 60gms sample from the asteroid Bennu. Thanks to the OSIRIS-Rex mission, scientists now have a better understanding of Bennu’s orbital path and its whereabouts for the next 200 years. The spacecraft is expected to return samples to Earth during September 2023, with about 400gms of materials.
According to scientist Davide Farnocchia, from NASA’s Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in Pasadena, California, and the lead author of this study, the odds of Bennu hitting Earth in the next century is quite low and shouldn’t be of immediate concern.
Bennu will pass Earth within half the distance of the moon in 2135. Based on earlier telescopic observations, it was determined that Earth’s gravity could put the asteroid’s future path on a collision course with the Earth in the 2200s. However, based on the data from OSIRIS-Rex, it may not be the case.
Bennu is not a doomsday asteroid; even if it strikes Earth, it will leave a crater 10 to 20 times its size and devastate an area 200 times that of the crater – according to Lindley Johnson, NASA’s planetary defense officer.
NASA is launching an exploratory mission in November to hit an asteroid and knock it off-course. In one hundred years from now, our technology would be different, and we will have measures to deflect such asteroids.