Nuclear weapon could be used to defend Earth from asteroid 2024 YR4, astronomer says

A nuclear weapon could potentially be sent into space to deflect an asteroid heading Earth's way, an astronomer has told Sky News.

Dr David Whitehouse said the measure could be taken against a space rock the size of a football pitch which is being monitored by the European Space Agency (ESA) and could strike the planet in a little over seven years.

The asteroid, called 2024 YR4 and measuring 100m by 40m, is currently at a distance of around 27 million miles and is edging away.

However, its path will cross our orbit on 22 December 2032 and was initially estimated to have a one in 83 chance of a direct hit.

Speaking to Sky News' Kay Burley, Dr Whitehouse said that had now dropped to a one in 67 chance, which he said was "unacceptable to ignore".

He added: "I think this has the potential to be very serious indeed."

In comparison, the astronomer said the chance of winning the lottery was one in 14 million.

"So, we have to keep a close eye on this object because it could turn out to be the most dangerous thing in space," he added.

Dr Whitehouse explained the "orbit will be refined" which will most likely lead to a lower possibility, but experts only have a "couple of months" to observe the asteroid before it disappears out of sight until 2028.

He said: "And that's the time we will have to take measures to deflect it. So, we've got some very serious decisions to make. We cannot ignore this rock.

"It's the highest probability of an impact I can recall. And it has the potential, the possibility for being an emergency for planet Earth."

The Space Mission Planning Advisory Group, which is chaired by the ESA, will discuss the latest observations of the asteroid at a meeting in Vienna next week.

If the impact risk is confirmed it will make official recommendations to the United Nations and work may begin on options for a "spacecraft-based response to the potential hazard", the agency said in a statement.

Dr Whitehouse said emergency deflection measures may need to be considered, including reaching the rock in 2028 in an attempt to nudge it "slightly out of its orbit" so that four years later it misses Earth.

Just over two years ago, NASA smashed a spacecraft into the 160m-wide asteroid Dimorphos and successfully changed its orbit.

Dr Whitehouse said: "We might even have to consider the severe measures of sending up a nuclear weapon to the surface of this asteroid in order to deflect it further."

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On average, the Earth takes a direct hit from an asteroid of a similar size once every few thousand years.

In 1908, a slightly smaller asteroid - thought to have measured 60m across - exploded over Siberia. It flattened 80 million trees over an area of 830 square miles.

Dr Whitehouse said: "I can't stress strongly enough that this is a threat that's not a bit of astro fun, that's not a bit of 'gosh, isn't it amazing?'

"This actually could turn out to be a serious threat to our planet."

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