Nasa finds and tracks asteroids in the hope of preventing dangerous ones from hitting Earth (Picture: Getty Images/Science Photo Libra)
Filmmakers have long been fascinated by apocalyptic asteroids and how the world would react if one was hurtling towards us.
In 1998’s blockbuster Armageddon, the US sends a bunch of oil drillers into space to tackle the problem, while in 2021’s black comedy Don’t Look Up most people choose to ignore the issue (though in this case the asteroid is a metaphor for climate change).
But what would actually happen? Well, hopefully astronomers would find the asteroid in good time, ideally years before it’s predicted to hit earth, to give the world time to stop it striking.
In the US, Nasa has its own Planetary Defense Coordination Office dedicated to finding, tracking and assessing the risk associated with potential hazardous asteroids.
In a video, Nasa planetary defense expert Dr. Kelly Fast said: ‘It’s important to find asteroids before they find us, in case we need to get them before they get us.
‘An asteroid impact is the only natural disaster that could be prevented. Nasa’s Planetary Defense Coordination Office supports projects to discover and track asteroids and to calculate their orbits far into the future.’
She said that if an asteroid threat is discovered years, or ideally decades in advance, a deflection mission might be possible.
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She added: ‘There are a few technologies and techniques that Nasa is studying to deflect an asteroid on a course to impact Earth.’
One of these is DART – Double Asteroid Redirection Test – which it trialled in 2021.
The test involved crashing an unmanned spacecraft into a small asteroid to see if the asteroid could be deflected away from earth.
The mission was a success and Nasa plans to test more deflection techniques
Among them is the ‘gravity tractor’ technique, Business Insider reports. It involves positioning a spacecraft next to the asteroid and allow the gravitational interaction to pull the asteroid out of its orbit.
Nasa is also working on a technique that uses an ion beam to change an asteroid’s course.
The space agency is of course not the only organisation keeping an eye on potentially dangerous asteroids. There are people working in the field across the world and many form part of the International Asteroid Warning Network.
Nasa is developing technology to deflect dangerous asteroids (Picture: Getty Images/iStockphoto)
If anyone spots a deadly asteroid threatening Earth, the party member would share their observations with the IAWN network to verify their findings and asses the danger.
If the asteroid was heading for the US, Nasa would inform the White House and the US government would issue a statement to the public.
If it was big enough to pose an international threat, IAWN would contact the United Nations Office of Outer Space Affairs.
To be considered ‘potentially hazardous’ an asteroid needs to be around 460ft or more in diameter and could come within 4.65 million miles of Earth (about half the distance between the Earth and the sun).
It’s believed there are around 2,300 potentially hazardous asteroids out there right now.
An asteroid must be 460ft or more in diameter to be considered hazardous (Picture: Getty Images)
Some 150 of them are more than 0.6 miles in diameter, which is large enough to cause serious damage to Earth.
One asteroid scientists have their eye on is Bennu, which they say has a 1 in 2,700 chance of colliding with Earth in 2182.
If it does it could strike with the force of 22 atomic bombs.
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Right now however, there’s more fascination than fear over Bennu, with Nasa’s Osiris-REx mission delivering a sample of space rock in September after a seven-year trip to the asteroid.
It suggested Bennu may have come from an ancient oceanic world – that could have been home to alien life.
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