Experts believe that it could take multiple impacts of a large human-made device to deflect an asteroid like Bennu. It has a very small chance of striking Earth within a century.
California scientists have used projectiles to shoot at meteorites in an attempt to mimic the most effective methods for altering the trajectory of an asteroid.
According to the results so far, an asteroid like Bennu that is rich in carbon could need several small bumps to charge its course.
NASA announced earlier in the month that Bennu has a slight higher chance of reaching Earth, despite being only a third of an inch wide.
The space agency upgraded the risk of Bennu impacting Earth at some point over the next 300 years to one in 1,750.
Bennu also has a one-in-2,700 chance of hitting Earth on the afternoon of September 24, 2182, according to the NASA study.
Since the 1960s scientists have been trying to prevent an asteroid ever striking Earth. However, previous attempts have tended to involve theories about how to break the cosmic object down into many thousands.
These pieces can potentially be zoomed towards Earth, and could pose almost the same danger and threat to humanity as original asteroid.
An alternative approach called kinetic impacts deflection (KID) involves firing something into the space which gently bumps an asteroid out of orbit away from Earth but keeps it intact.
Recent KID efforts were outlined at the 84th annual meeting of the Meteoritical Society held in Chicago this month and led by Dr George Flynn, a physicist at State University of New York, Plattsburgh.
Flynn told The New York Times that you might need multiple impacts. ‘It [Bennu]Although you may miss, it’s not enough.
NASA’s Ames Vertical Range has been home to researchers since the Apollo era. It was built at Moffett Federal Airfield, California, Silicon Valley.
The projectiles were small and spherical, hitting meteorites suspended on pieces of nylon string.
The team used 32 meteorites – which are fragments of asteroids that have fallen to Earth from space – that were mostly purchased from private dealers.
They were able to study the effect of momentum on an object made by humans firing at an asteroid, and not just how it would be destroyed.
Dr Flynn stated, “If you cut it in pieces, some pieces might still be on an collision course with Earth.”
Carbonaceous chondrite (C-type) asteroids, such as Bennu, are the most common in the solar system.
They are darker than other asteroids due to the presence of carbon and are some of the most ancient objects in the solar system – dating back to its birth.
According to the findings from experiments at AVGR, the type of asteroid being targeted (and how much carbon it has in it) may dictate how much momentum would be directed at it from any human-made KID device.
Researchers found that C-type meteorites can withstand less than one-sixth as much momentum before they shatter.
‘[C-type]Experts concluded that asteroids can be more difficult to disperse without disrupting than normal chondrite asteroids.
“These results suggest that multiple consecutive impacts might be necessary to disrupt rather than deflect asteroids.
Therefore, around 160 years in the future – when Bennu is most likely to collide with Earth, according to NASA – a KID device would have to give it a series of gentle nudges to prevent it from breaking up and sending dangerous splinter fragments flying towards Earth.
NASA’s recent study about Bennu, published in the journal Icarus, did point out there is more than a 99.9 per cent probability Bennu will not smash into Earth over the next three centuries.
NASA stated in a statement that Bennu is still one of the most dangerous known asteroids, despite its low chance of hitting Earth.