A Building-Sized Asteroid Approaches
Astronomers have been closely tracking asteroid 2024 YR4, a space rock with the potential to cause significant destruction. First discovered in December 2024, the asteroid has been labelled a “city-killer” due to its size and potential impact.
NASA’s latest observations confirm that 2024 YR4 measures between 174 and 220 feet (53-67 metres) in diameter. That’s roughly the height of a 10-storey building. Despite initial concerns, astronomers now say there is no (or a little) chance of it hitting Earth in 2032.
Illustration showing the potential positions of asteroid 2024 YR4 on December 22, 2032, based on data from April 2, 2025.
Credit: NASA JPL/CNEOS
Is Earth in Danger?
Early calculations gave 2024 YR4 up to a 3.1% chance of striking Earth in December 2032. However, NASA has ruled out this possibility.
Kelly Fast, a planetary defence officer at NASA, said, “Astronomers are watching 2024 YR4 closely, trying to learn everything they can before it disappears from view by mid-April.”
Instead of heading toward Earth, the asteroid now has a 3.8% chance of hitting the Moon in 2032. Even if it impacts the Moon, scientists say it won’t alter its orbit or pose a danger to Earth.
Instead of heading toward Earth, the asteroid now has a 3.8% chance of hitting the Moon in 2032.
How Was It Discovered?
Astronomers at the University of Hawaii’s ATLAS telescope first spotted 2024 YR4 on December 27, 2024. Its elongated orbit takes it far beyond Mars and Jupiter before it returns near Earth.
Because of its unique path, 2024 YR4 had gone undetected in previous flybys. As technology improves, astronomers expect to discover more like it.
Also Read: Asteroid 2024 YR4: New Data Shifts Threat from Earth to Moon
What If It Did Hit Earth?
NASA has classified 2024 YR4 as a “city-killer” because of its size. If it were to strike a populated area, it could cause massive destruction.
In 1908, a similar-sized asteroid exploded over Siberia in the Tunguska event. That blast flattened 2,000 square kilometres of forest. Scientists believe an impact from 2024 YR4 could cause similar damage.
Tracking Future Risks
While 2024 YR4 won’t hit Earth in 2032, astronomers are still monitoring its long-term trajectory.
NASA’s Davide Farnocchia explained, “It currently has a 1.1% chance of striking Earth on Dec. 22, 2047.”
A 1.1% chance may seem small, but space agencies take any potential impact seriously. Future observations will refine the asteroid’s path and determine if it remains a threat.
Why Observing Asteroids Matters
NASA’s James Webb Space Telescope recently captured images of 2024 YR4 to learn more about its composition. These observations help scientists understand how asteroids behave and what risks they pose.
Andy Rivkin, an asteroid expert at Johns Hopkins University, explained, “We expect more possible impactors to be found in coming years as more sensitive asteroid search programs begin operation.”
Should We Be Worried?
For now, there is no immediate danger. NASA has confirmed that 2024 YR4 will not strike Earth in 2032. However, astronomers will continue monitoring it, as its long-term path remains uncertain.
The discovery of 2024 YR4 highlights the importance of planetary defence. Scientists are developing new methods to detect and deflect potential threats before they become a danger to Earth.
Final Thoughts
While 2024 YR4 is a reminder that space is unpredictable, current data shows that Earth is safe. The asteroid will soon disappear from view until 2028, when astronomers will track its path again.
The good news? For now, the “city-killer” remains just a fascinating space rock passing by.
