A near-Earth asteroid discovered by astronomers late last year that showed a rising potential for colliding with Earth has been downgraded, according to planetary defense experts.
The update, provided by the European Space Agency’s (ESA) Planetary Defence Office on Tuesday, revealed that further analysis of asteroid 2024 YR4 has reduced earlier estimates about the probability of its impact with Earth in 2032 to a minuscule 0.001%.
Shortly after its discovery last year, the near-Earth object received significant attention after it showed a small but rising probability of impacting Earth within the next decade.
Now, ESA tracking scientists say the potential threat from the asteroid, which reached a probability of impact as high as 2.8% before being downgraded, is extremely low.
Asteroid Puts Planetary Defense Scientists on Alert
Asteroid 2024 YR4 was discovered on December 27, 2024, thanks to the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile. Following its initial detection, the space object was flagged by automated warning systems, including the ESA’s ‘Aegis’ software that monitors the orbit and impact potential of near-Earth objects by the agency’s Planetary Defence Office.
At an estimated 40 to 90 meters in width, the asteroid would be large enough to cause significant damage to any region on Earth where an impact occurred, particularly if it were to occur near a major population center.
Responding to the potential threat, the ESA’s Near-Earth Object Coordination Centre spent the next two months working with other institutions to observe the asteroid’s path, obtaining data that helped them refine the object’s orbit with additional telescopic data.
The new data only added to researchers’ concerns, raising the impact potential to its peak level—roughly 2.8%—earlier this month, with a possible collision projected for December 22, 2032.
New Data Lowers Chances of Impact
Soon after the new projections were made, further data collected by the European Southern Observatory’s Very Large Telescope significantly reduced those figures by roughly half. Just days later, even more recent data appeared to give the most accurate projections, ruling out nearly all remaining impact scenarios.
Asteroid 2024 YR4 has now officially been downgraded from Level 3 to Level 0 on the Torino Impact Hazard Scale, placing it in a category of near-Earth objects that are unlikely to present any credible risk. The ESA also removed the asteroid from its list of potentially threatening space objects, and the International Asteroid Warning Network has formally concluded its monitoring efforts.
The Ups and Downs of Detecting Dangers from Space
Asteroid tracking efforts like these represent one of the most critical components of our current planetary defense strategies. Ultimately, they provide data that will help us prepare for any threats from space that may arise in the coming decades and plan how to address them.
Although some may rightly argue that all the fuss that erupted over asteroid 2024 YR4 was premature, experts note that fluctuations in impact probability following the discovery of new asteroids are common and influenced by various factors. These include uncertainties in the orbits of newly discovered asteroids, which narrow over time with the help of ongoing observations.
In most cases, continued observation of the orbital behavior of near-Earth objects eliminates any possibility of dangers they may represent.
Although 2024 YRT is no longer a threat, that doesn’t mean astronomers plan to cease their observations anytime soon since the asteroid still represents an object of interest for a range of future studies. In the months ahead, astronomers plan to observe the space rock using NASA’s James Webb Space Telescope, which will help scientists collect additional data that may help plan for planetary defense scenarios.
Additionally, survey capabilities made possible through technologies like the ESA’s Flyeye telescopes further enhance detection capabilities, enabling astronomers to spot even more near-Earth objects that might have successfully evaded scientists until now.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.