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1 month ago
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Out in the depths of space, somewhere in between Mars and Jupiter, is a newly discovered asteroid that’s breaking records.
Astronomers have spotted a celestial rock the size of seven football pitches that is spinning faster than they’ve ever seen before.
The asteroid, named 2025 MN45, is 710 metres in diameter and completes a full rotation every 1.88 minutes.
The fact that it spins so rapidly has baffled experts, who say it must consist of solid rock in order to maintain its shape.
‘Clearly, this asteroid must be made of material that has very high strength in order to keep it in one piece as it spins so rapidly,’ Sarah Greenstreet, who leads the Rubin Observatory’s Solar System Science Collaboration’s Near-Earth Objects and Interstellar Objects working group, said.
‘We calculate that it would need a cohesive strength similar to that of solid rock.
‘This is somewhat surprising since most asteroids are believed to be what we call “rubble pile” asteroids, which means they are made of many, many small pieces of rock and debris that coalesced under gravity during Solar System formation or subsequent collisions.’
While it is currently out in the asteroid belt, hundreds of millions of kilometres away, asteroids and comets have previously been ‘nudged’ into Earth’s neighbourhood by the gravity of nearby planets.
This artist’s illustration depicts 2025 MN45 — the fastest-rotating asteroid with a diameter over 500 meters that scientists have ever found
The lightcurve of the asteroid - the y-axis shows the asteroid’s brightness, and the x-axis shows its phase, or where it is in its rotation
The sighting forms part of a much larger discovery, as scientists have detected 1,900 new asteroids cruising about our Solar System that have never been seen before.
Within this flurry are 19 super and ultra-fast rotating asteroids – with 2025 MN45 taking the new record for the fastest-spinning asteroid with a diameter over 500 meters that astronomers have found.
For their study, researchers collected data over the course of about 10 hours across seven nights in April and May of last year.
They used the Rubin Observatory’s LSST Camera – the largest digital camera in the world – to capture the night sky.
‘Discoveries like this exceptionally fast-rotating asteroid are a direct result of the observatory's unique capability to provide high-resolution, time-domain astronomical data, pushing the boundaries of what was previously observable,’ Regina Rameika, from the US Department of Energy, said.
As asteroids orbit the Sun, they also rotate at a wide range of speeds, the researchers explained.
These spin rates not only offer clues about the conditions of their formation billions of years ago but also tell us about their internal composition and evolution over their lifetimes.
In particular, an asteroid spinning quickly may have been sped up by a past collision with another asteroid, suggesting that it could be a fragment of an originally larger object.
Most asteroids can be found orbiting our Sun between Mars and Jupiter within the main asteroid belt
An illustration of the main asteroid belt, orbiting the Sun between Mars and Jupiter, where asteroid 2025 MN45 can be found
This image, one of the first released by Rubin Observatory, exposes a Universe teeming with stars and galaxies — transforming seemingly empty, inky-black pockets of space into glittering tapestries for the first time
‘Fast rotation also requires an asteroid to have enough internal strength to not fly apart into many smaller pieces, called fragmentation,’ the team said in a release.
‘Most asteroids are ‘rubble piles’, which means they are made of many smaller pieces of rock held together by gravity, and thus have limits based on their densities as to how fast they can spin without breaking apart.
‘For objects in the main asteroid belt, the fast-rotation limit to avoid being fragmented is 2.2 hours; asteroids spinning faster than this must be structurally strong to remain intact.
‘The faster an asteroid spins above this limit, and the larger its size, the stronger the material it must be made from.’
Within the main asteroid belt are space rocks ranging in size from 530km (329 miles) to just 10 metres (33 feet) in diameter.
‘Sometimes, asteroids and comets are nudged into Earth’s neighbourhood by the gravity of nearby planets,’ NASA says.
However, they explained that it is ‘highly unlikely’ an asteroid large enough to cause widespread damage will impact Earth for the next 100 years or more.
The new findings were published in The Astrophysical Journal Letters.
WHAT COULD WE DO TO STOP AN ASTEROID COLLIDING WITH EARTH?
Currently, NASA would not be able to deflect an asteroid if it were heading for Earth but it could mitigate the impact and take measures that would protect lives and property.
This would include evacuating the impact area and moving key infrastructure.
Finding out about the orbit trajectory, size, shape, mass, composition and rotational dynamics would help experts determine the severity of a potential impact.
However, the key to mitigating damage is to find any potential threat as early as possible.
NASA and the European Space Agency completed a test which slammed a refrigerator-sized spacecraft into the asteroid Dimorphos.
The test is to see whether small satellites are capable of preventing asteroids from colliding with Earth.
The Double Asteroid Redirection Test (DART) used what is known as a kinetic impactor technique—striking the asteroid to shift its orbit.
The impact could change the speed of a threatening asteroid by a small fraction of its total velocity, but by doing so well before the predicted impact, this small nudge will add up over time to a big shift of the asteroid's path away from Earth.
This was the first-ever mission to demonstrate an asteroid deflection technique for planetary defence.
The results of the trial are expected to be confirmed by the Hera mission in December 2026.
