Right, everybody can breathe a small sigh of relief as we've got some good news for once...
NASA has significantly lowered the risk of asteroid 2024 YR4 impacting Earth in 2032 after further analysis and observations.
Once considered a potential “city killer,” the asteroid was initially tracked with a small but notable chance of collision, sparking concern among astronomers and the public.
However, new data now confirms that there is no significant impact risk for at least the next century.
The latest calculations from NASA’s Jet Propulsion Laboratory (JPL) and its Center for Near-Earth Object Studies (CNEOS) have refined the asteroid’s trajectory, showing that the range of possible locations for 2024 YR4 on December 22, 2032, no longer includes Earth.
However, a 1.7% chance remains for the asteroid to impact the Moon on that date.
NASA will continue monitoring 2024 YR4 using its planetary defense resources, and the James Webb Space Telescope is scheduled to observe the asteroid in March to refine its size and composition.
From Potential Impact to Safe Passage
When first spotted in December 2023, asteroid 2024 YR4 was closely watched by NASA and international space agencies due to its possible risk to Earth.
The initial impact probability fluctuated, with early estimates suggesting a 1-in-83 chance of collision in 2032. Those odds gradually increased over time, reaching a peak of 1-in-38 (2.6%), raising concerns among scientists and prompting further analysis.
If 2024 YR4 had collided with Earth, its estimated size — between 40 and 90 meters wide — would have resulted in an explosion with the force of 7.7 megatonnes of TNT, approximately 500 times the energy of the atomic bomb dropped on Hiroshima.
Experts warned that such an impact could flatten an entire city, similar to the Tunguska event in 1908, which devastated 800 square miles of Siberian forest.
At the time, NASA’s Torino Scale, which measures the potential threat of near-Earth objects (NEOs), classified the asteroid as a Level 3 risk, meaning it merited continued monitoring due to its chance of causing localized destruction.
Tracking the “City-Killer” Asteroid
As monitoring efforts intensified, NASA, the European Space Agency (ESA), and other institutions collected new data to refine the asteroid’s trajectory.
Early calculations identified a "risk corridor" — a potential impact zone that spanned South America, sub-Saharan Africa, the Indian subcontinent, and parts of Asia, including cities like Bogotá, Mumbai, Kolkata, Lagos, and Dhaka.
David Rankin, an engineer with the NASA-funded Catalina Sky Survey Project, explained that while 2024 YR4 was similar in size to past significant asteroid impacts, ongoing monitoring would likely reveal a less alarming scenario.
“People should absolutely not worry about this yet,” Rankin said at the time. “Impact probability is still very low, and the most likely outcome will be a close approaching rock that misses us.”
Refining the Data & Future Monitoring
As predicted by astronomers, further observations led to the risk being completely ruled out for Earth.
The new calculations, aided by NASA’s Sentry system, eliminated the possibility of impact, shifting 2024 YR4’s projected path safely away from our planet.
However, there is still a small chance — 1.7% — that the asteroid could impact the Moon on December 22, 2032. While this remains unlikely, NASA and other space agencies will continue monitoring the asteroid’s trajectory.
The James Webb Space Telescope (JWST) will observe the asteroid in March 2025 to further refine its size and composition.
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Understanding these factors will help scientists determine the asteroid’s behavior in space and its ability to survive atmospheric entry if it were ever on a collision course in the distant future.
Planetary Defense Lessons from 2024 YR4
Despite the initial concern surrounding 2024 YR4, the asteroid provided an invaluable opportunity for NASA and its partner agencies to test their planetary defense strategies and response procedures.
In 2022, NASA successfully tested its Double Asteroid Redirection Test (DART) mission, proving that an asteroid’s trajectory could be altered through kinetic impact. China is also planning its own asteroid-deflection test in 2027. These efforts continue to refine global preparedness for potential future threats.
NASA’s Planetary Defense Coordination Office (PDCO) will keep tracking all known near-Earth asteroids that could pose a risk, ensuring continued vigilance.
For now, though, 2024 YR4 has been officially downgraded from an Earth-impact threat—a reassuring conclusion to months of uncertainty.