‘Planetary defence team’ being assembled as China joins US & Europe bracing for ‘city-killer’ asteroid strike
CHINA is assembling a planetary defence team after a giant “city-killer” asteroid was discovered hurtling towards Earth.
The emergency measures come after scientists warned we may not have enough time to divert the huge space rock using a “sacrificial rocket” – the preferred method.
The odds of a collision with between the asteroid and our planet have been slashed to a 1-in-43 chance.
The giant boulder rocketed to the top of Nasa’s impact risk list when it was discovered – and its threat level has only crept up with further calculations.
Scientists say the enormous rock, dubbed 2024 YR4, is between 40 and 100 metres wide, and would blow a crater the size of a city into the Earth’s crust – with the potential for thousands of deaths.
It poses the highest risk ever recorded for an asteroid by the European Space Agency (ESA) – and the calculated threat has breached the threshold for triggering an international response.
Now, a special projects cell in China‘s State Department for Science and Technology has posted job adverts for three “planetary defence” posts.
The centre – China’s mission control for aerospace engineering – is taking on graduate science whizzes to advance asteroid monitoring and build early warning systems.
ESA projections show 2024 YRA’s path could intersect with Earth’s orbit at Christmas time in 2032 – specifically 8.52am GMT on Wednesday, December 22.
With rising concerns about the chances of impact, researchers have suggested various deflection methods – including solar lasers, nuclear bombs or – most likely – kinetic impactors.
The latter option involves scientists launching a spacecraft at the asteroid to knock it off orbit.
KNOCK IT WITH A ROCKET
Mathematicians have calculated that crashing a “sacrificial” spacecraft into the side of a speeding asteroid less than one kilometre across – like 2024 YRA – would be powerful enough to divert it.
However, we may already have run out of time to use this method, according science writer Dr Robin George Andrews.
He said on X: “I’ve often [been] told you need 10 years or more to build, plan and execute an asteroid deflection mission.
“Now let’s look at 2024 YR4. We have less than eight years to potentially deal with it, if needed.
“I’m not saying a kinetic impactor mission, or missions, couldn’t work.
“But we don’t have much time, and we don’t have enough info about this rapidly fading asteroid to properly inform our planetary defense decisions yet.”
Even if we did have time, he noted the kinetic impactor method may have unintended consequences.
In fact, he warned that the technique used two years ago in NASA‘s DART mission could be like “turning a cannonball into a shotgun spray”, increasing the possible devastation on Earth.
The London-based scientist, who specialises in volcanology but writes generally on science, added: “I’m seeing a lot of people claim that, if it is going to impact Earth in 2032, we can use a DART-like spacecraft to ram it out of the way.
“Well, not necessarily. The DART mission was fab, but might not be able to stop 2024 YR4.”
In 2022, Nasa’s DART spacecraft was deliberately driven into the side of Dimorphos – a small asteroid “moonlet”.
The mission was mainly to test Nasa’s planet defence systems, and was deemed a big success.
Dr Andrews said: “As DART smashed into the asteroid, lots of debris flew back off the asteroid, acting like a rocket jet and giving it more of a push.”
But he warned that it does not prove the method can be used for all kinds of asteroid deflection.
He said: “Asteroids like Dimorphos, and smaller, tend to be rubble piles: not solid single rocks, but boulders weakly bound by their own gravity.
“Hitting them just right can produce that debris-like thrust effect, but if you hit them too hard, you’ll shatter them.
GOING NUCLEAR
Another option for dodging disaster is to detonate a nuclear bomb near the the asteroid – and Dr Andrews urged researchers not to rule it out.
He suggested that scientists may “break an awkward taboo” of using a nuclear weapon against 2024 YR4 “which would provide a bigger punch than DART”.
The European Union-funded NEO Shield consortium said last week that the use of a nuclear bomb would be a last resort.
While the idea of sending a nuclear weapon into space to stop a potentially deadly asteroid sounds like fiction thanks to movies like Armageddon, it is one of the options available to scientists.
A carefully executed explosion close to the surface of the asteroid would be carried out in the hope that the rock shatters into smaller fragments that would burn up in the atmosphere.
However, larger chunks could still be big enough to survive the atmosphere and rain down on a larger area of Earth.
Another nuclear option would be to detonate the nuclear weapon further away from the asteroid with the idea that the explosion would damage the surface of the rock and knock it off course.
If carried out correctly, there would be minimal damage to the asteroid, and therefore no risk of chunks of space rock falling to Earth.
But detonating a nuclear weapon in space is not only tricky and riskY – it’s also strictly against UN treaties.
Ian Carnelli, a planet defence expert at the ESA, told The Telegraph: “It is a lot more complex with a nuclear device, and that is before you get into the political discussion because nuclear explosions in space are banned by UN treaties.
‘CITY-KILLER’
Astronomer Dr David Whitehouse first noted the chances of a disastrous collision increasing as he said the asteroid is “unacceptable to ignore”.
An impact would unleash energy hundreds of times greater than that of the Hiroshima bomb with a blinding flash as shock waves that would flatten anything for miles.
One expert called it a potential ‘city-killer’ telling CBS that “if you put it over Paris or London or New York, you basically wipe out the whole city and some of the environs.”
If the asteroid explodes near the coastline, a life-threatening tsunami could occur.
As fears of impact increase, an international team of astronomers has been granted use of the iconic James Webb Space Telescope (JWST) so they can determine how much damage the asteroid may cause.
Astronomers are set to use the JWST in March to measure the exact size of 2024 YR4 and make any final calculations around its orbit.
The JWST, used by both the ESA and NASA, will take images of 2024 YR4 from its position a million miles away from Earth.
A second round of observations will also take place in May to determine how it has moved within a few months.
At the moment, scientists believe the asteroid could be up to 300ft wide – the same size as New York‘s Statue of Liberty or London‘s Big Ben.
While scientists attempt to assure people that asteroid 2024 YR4 will most likely miss Earth, Dr Andrews warns that we must be serious about the methods we use if it doesn’t.
“We have to be wary of trying to save the world but accidentally making the problem worse,” he warned.
The Space Missing Planning Advisory Group, chaired by the ESA, has discussed the latest observations of 2024 YR4 at a meeting in Vienna.
They have given astronomers more time to determine their estimate of the asteroid’s orbit.
If the group believes there is a risk of a hit, it will make official recommendations to the United Nations and discuss options for a “spacecraft-based response to the potential hazard.”
Past Earth-threatening asteroids
MANY asteroids spotted in the past have been deemed a risk to Earth.
But only one has ever been diverted by human intervention.
In 2022, Nasa’s DART spacecraft was deliberately driven into the side of Dimorphos – a small asteroid “moonlet”.
The mission was mainly to test Nasa’s planet defence systems, and was deemed a big success.
There have been a number of other asteroids that have threatened the Earth, including:
- Chicxulub Impactor: This asteroid smashed into the Earth around 66 million years ago and is believed to have wiped out the dinosaurs
- 2004 FU162: In March 2004, this 33ft-wide meteoroid passed 6,500 km above Earth
- 1996 JA1: In May 1996, this space rock passed Earth at a distance of 450,000 km
- 99942 Apophis: This 1,100ft-wide asteroid was considered one of the most dangerous asteroids that could impact Earth. However, a radar observation campaign in 2021 concluded that it poses no risk to Earth for at least 100 years
- 1979 XB: This 2,165ft-wide asteroid had an estimated 1 in 1.8 million chance of impact
- 2007 FT3: This 0.6-mile-wide asteroid had an estimated 1 in 10 million chance of impact on March 3, 2030
- 7482 (1994 PC1): This 3,609ft-wide asteroid had its closest approach on January 18, 2022