The ‘city killer’ asteroid 2024 YR4 may not be on a collision course with Earth anymore.
But NASA has raised the odds of it hitting the moon in just seven years’ time.
According to the space agency, there’s now a 4.3 per cent chance that 2024 YR4 will smash into the moon on December 22, 2032.
The impact event could be visible from Earth as a bright flash of light, as lunar material is ejected into space.
Only discovered at the end of last year, 2024 YR4 is somewhere between 174 and 220 feet (53 and 67 metres) in diameter – around the same size as a Boeing 747.
If the space rock were to hit Earth, it would create a blast equivalent to detonating 7.7 megatons of TNT and leave a 3,000-foot-wide crater in the ground.
The shockwave radiating out from the impact would wipe out an area the size of a major city, which is why it has been designated a ‘city-killer’.
Fortunately, the chance of it hitting Earth is effectively nil, but the new NASA observations increase the likelihood of it hitting the moon.
The ‘city killer’ asteroid 2024 YR4 may not be on a collision course with Earth anymore . But NASA has raised the odds of it hitting the moon in just seven years’ time (stock image)
NASA has raised the odds of asteroid 2024 YR4 hitting the moon in just seven years time. Captured here is 2024 YR4 as observed by the Magdalena Ridge telescope in New Mexico, January 27, 2025
Impact probability 4.3 per cent: The chances of the rock hitting the moon will likely continue to rise and fall. This NASA image shows the range of possible locations – represented by yellow points – of 2024 YR4 on December 22, 2032
The new odds are slightly raised from the previous 3.8 per cent chance of 2024 YR4 colliding with the moon, according to NASA.
‘As data comes in, it is normal for the impact probability to evolve,’ said Molly Wasser, public affairs officer for NASA’s Planetary Defense Coordination Office.
At more than 30 million miles away, asteroid 2024 YR4 is now too distant to detect with telescopes on Earth.
So NASA has been relying on observations from the James Webb Space Telescope (JWST), which is positioned in space about 1 million miles away from us.
Asteroid 2024 YR4 is currently on a wide ‘elliptical’ (not perfectly circular) orbit around the sun, taking it even further from us before.
Further updates will not be possible until 2028 when the space rock comes back around towards Earth and becomes bright enough to be detected again.
Bu before it escaped from its view, JWST managed to collect one more observation of the object, made using its near-infrared camera last month.
‘With the additional data, experts from NASA’s Center for Near-Earth Object Studies at the agency’s Jet Propulsion Laboratory in southern California further refined the asteroid’s orbit,’ said Wasser.
Asteroid 2024 YR4 is currently on a wide ‘elliptical’ (not perfectly circular) orbit around the sun, while is taking it even further from us before it comes back around. This image shows the orbit 2024 YR4 in purple with the sun in the centre and orbits of planets (Mercury = cyan; Venus = yellow; Earth = dark blue; Mars = red). Note the asteroid’s position (purple dot) in relation to Earth (dark blue dot) about a month before an impact might happen
When it zooms back towards the inner solar system, the asteroid will reach an astonishing 85 million miles per hour (38,000 km per second).
Asteroids speed up as they approach the sun because of the increased gravitational pull from the sun as they get closer – a bit like an object travelling faster the closer it gets to the ground on Earth.
In the event that the asteroid did hit the moon, it would not alter our natural satellite’s orbit around Earth, according to NASA.
However, it would create a huge crater, ejecting rocky lunar material into space, and generating a bright flash, which should be visible from Earth.
The impact event would be the first time scientists could watch a known asteroid create a lunar crater in real-time.
The data gathered from this impact could help scientists understand more about other craters on the lunar surface.
It is worth nothing that there is a 95.7 per cent chance that it won’t hit the moon at all, as it stands – and the probability will likely continue to rise and fall.
This image provided by the European Space Agency on April 2, 2025, captured by NASA’s James Webb Space Telescope, shows asteroid 2024 YR4
Asteroid 2024 YR4 is about the same size as the Tunguska asteroid, which caused the largest impact event in recorded history when it shot through Earth’s atmosphere in 1908, flattening 830 square miles (2,150 square km) of forest (pictured)
Asteroid 2024 YR4 was discovered on December 27, 2024 – and soon became a global matter of concern.
2024 YR4 set alarm bells ringing at the world’s space agencies in February when its probability of hitting Earth reached a peak of one-in-32, or 3.1 per cent.
Thankfully, about a week later, the odds were vastly downgraded just 0.0039 per cent, or one in 26,000.
Asteroid 2024 YR4 is thought to be at least the same size as the Tunguska asteroid – which had an estimated diameter of 130 feet, according to NASA.
Tunguska caused the largest impact event in recorded history when it shot through Earth’s atmosphere in 1908, flattening 830 square miles (2,150 square km) of forest.
Many lost consciousness and at least three people passed away as a direct consequence of the Tunguska event, according to a 2019 study.
Experts are concerned that we may detect a civilization-threatening Earth-bound asteroid too late, with not enough time for a mission to knock it off course.
