WASHINGTON, D.C. — Astronomers are keeping a close watch on a newly discovered near‐Earth asteroid that, while highly unlikely to hit Earth, remains under intense international scrutiny. Designated 2024 YR4, the object was first detected on Dec. 27, 2024, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, and it now tops the risk list for potential impact events.
Estimated to be between 40 and 100 meters in diameter, 2024 YR4 is classified as an Apollo-type asteroid—its orbit crosses that of Earth. Current calculations indicate a roughly 2.2–2.3% chance that the asteroid could impact Earth on Dec. 22, 2032, though astronomers emphasize that this probability is expected to fall to zero as additional observations narrow the uncertainty in its trajectory.
“Initial impact probabilities often rise as we first acquire data and then drop precipitously once we extend the observation arc,” said one NASA official. Agencies including NASA’s Center for Near-Earth Object Studies (CNEOS), the European Space Agency’s (ESA) Planetary Defence Office, and international groups such as the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG) are pooling their resources to track the object.
According to the latest assessments, the asteroid’s orbit is elliptical, with a period of approximately four years, and it made a close approach to Earth on Dec. 25, 2024—just two days before its official discovery. Although the object is now receding from Earth and will become too faint for ground-based telescopes until its return in 2028, scientists are using the world’s most powerful instruments, including ESA’s Very Large Telescope and space-based infrared observatories, to refine its size, albedo, and orbital path.
If 2024 YR4 were to strike, models suggest the impact could release energy equivalent to roughly 7.7 to 8 megatons of TNT—comparable to the energy released by large nuclear devices. Such an event, while not posing a global threat, could cause severe localized damage over an area spanning tens of kilometers. For this reason, the asteroid is currently rated at level 3 on the Torino Impact Hazard Scale, which is reserved for objects large enough and with a non-negligible impact probability to merit continued attention.
Planetary defense experts have discussed several potential mitigation strategies should further observations confirm a risk. Among these, a kinetic impactor—similar in concept to NASA’s successful Double Asteroid Redirection Test (DART) mission in 2022—is seen as the most viable option. Other techniques, including nuclear deflection, remain a topic of ongoing technical and political debate.
“While a 2.3% chance of impact might sound alarming, the overwhelming likelihood remains that 2024 YR4 will pass by safely,” noted one ESA spokesperson. “Our current focus is to gather more data to shrink the uncertainty in its orbit. With each new observation, we expect the impact probability to drop.”
For now, scientists are urging calm as they continue monitoring the asteroid’s path. The situation remains dynamic, and updates are expected as new measurements become available. In the meantime, international space agencies stand ready with contingency plans to deflect the asteroid if future data ever suggest a sustained threat.