A 100-metre wide asteroid that has been compared to one that levelled 2200 square kilometres of forest in Russia in 1908 has a small change of hitting Earth in less than 10 years.
Spotted by NASA telescopes on December 27 last year, two days after it passed by Earth, the celestial body has been designated Asteroid 2024 YR4.
And its discovery has triggered the world’s planetary defence systems, with a 1.3 per cent chance it could hit Earth on December 22, 2032.
NASA’s Centre for Near Earth Object Studies recently said a potential impact zone included “the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia”.
Curtin University’s Dr Hadrien Devillepois, lead scientist in the Desert Fireball Network, said further observations between now and then would likely reveal the asteroid will miss – but that was not certain.
“So we need more observations, but crucially we need more observations spaced in time to precisely predict the asteroid’s course,” he said.
“In the unlikely event that it is on a collision course to Earth in 2032, the asteroid will have an explosive energy comparable to the Tunguska impact in 1908.
“The atmospheric explosion caused by the asteroid in Tunguska caused local devastation, flattening a large forest, and also possibly killed people”.
Dr Evie Kendal, form the Ethical, Legal, and Social Implications of Emerging Technologies research group at Swinburne University of Technology, said the discovery of the asteroid highlighted the need for a “global strategy” to deal with such incidents.
“Planetary defence technologies have been developed that could redirect an asteroid on an impact trajectory, but the ethico-legal governance issues for if and how we should deploy such systems have not been settled,” she said.
“NASA’s Double Asteroid Redirection Test (DART) mission demonstrated proof-of-concept for kinetic impactor technologies in 2022, colliding with the Dimorphos asteroid and successfully altering its path. But whose responsibility is planetary defence on a global scale?”
Curtin University’s Professor Fred Jourdan said that while it was unlikely, the asteroid could hit Earth with “potentially devastating consequences” and the planet needed a plan to push it off course or destroy it.
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“But this plan will need to rely heavily on knowing what the asteroid is made of and its structure: you don’t deflect asteroids that are made of a pile of rubble loosely bound together the same way you do with the ones made of a solid chunk or rocks,” he said.
“So detailed observations are key, with potentially sending a spacecraft to take accurate measurements. Hopefully, with only one per cent chance of impact, it won’t come to this.”
Professor of astrophysics Jonti Horner from the University of Southern Queensland, however, urged people “don’t panic”.
“The vast majority of Earth is empty space – and the bulk of the area at risk from the impact is open ocean – so the most likely outcome of an impact would that it produces a spectacular light show but no-one gets hurt,” he said.
“We’ll know more in 2028, when the asteroid flies by the Earth again – and observations then will allow us to learn more about the potential impact risk, and to begin planning should it turn out that the impact is going to happen.”
