A recently discovered 196-foot-wide asteroid, designated 2024 YR4, has caught the attention of astronomers worldwide after calculations revealed a 1-in-83 chance that it could impact Earth on December 22, 2032. While the probability remains low, this is one of the highest recorded impact risks for a near-Earth object (NEO) of this size. Currently 27 million miles away, 2024 YR4 is expected to make an extremely close approach, coming within 66,000 miles (106,200 km) of Earth. However, uncertainties in its orbital path leave open the possibility of a direct hit.
This discovery has propelled 2024 YR4 to the top of the European Space Agency’s NEO Impact Risk List and NASA’s Sentry Risk Table, prompting astronomers to closely monitor its trajectory. If it were to collide with Earth, the asteroid could either create a massive airburst in the atmosphere or form an impact crater, depending on its composition.
The Uncertainty of 2024 YR4’s Path
Tracking an asteroid’s orbit is an extremely complex task, requiring repeated observations to reduce uncertainty. Right now, 2024 YR4’s impact probability stands at 1 in 83, a figure that makes it one of the highest-risk objects ever recorded.
“Odds have slightly increased to 1 in 83,” noted David Rankin, an engineer at the Catalina Sky Survey and a leading asteroid tracker. “This is one of the highest probabilities of an impact from a significantly sized rock ever.”
Despite these alarming odds, astronomers urge caution before jumping to conclusions. Rankin reassured the public that, for now, the most likely outcome is a close pass rather than an impact. “People should absolutely not worry about this yet,” he stated. “Impact probability is still very low, and the most likely outcome will be a close approaching rock that misses us.”
Currently, the estimated risk corridor—the potential path along which an impact could occur—stretches from South America across the Atlantic to sub-Saharan Africa. However, Rankin noted that this prediction will likely change as more precise data becomes available. “It is just important to keep in mind that its orbit is still too uncertain to know if it will hit, and right now, the most likely outcome is a miss,” he explained. “This impact corridor estimation will eventually go stale with new observations and better orbit calculations.”
What We Know About the Asteroid
One of the key challenges in assessing 2024 YR4’s threat is that scientists still have limited data on its size and composition. These factors play a crucial role in determining the asteroid’s potential damage in the event of an impact.
“Size and composition are big players in possible damage, along with impact location,” Rankin emphasized. “It’s hard to constrain size and composition with the current orbital situation, as it’s outbound. Typically, the best way to constrain size is with radar observations, and those are not possible right now.”
Scientists estimate 2024 YR4 is about 196 feet (60 meters) wide, but this measurement is based on its absolute magnitude, which depends on how much sunlight it reflects. However, without radar imaging, this estimate could be off. “If the asteroid has a darker surface, that number is too small; if it has a more reflective surface, that number is too high,” Rankin explained.
Knowing the asteroid’s exact composition is also critical in predicting its potential impact effects. If 2024 YR4 is composed primarily of stony material, it could explode in the atmosphere, producing a massive airburst and fireball similar to the 1908 Tunguska event, which flattened 830 square miles of Siberian forest. “It is likely around the same size as the 1908 Tunguska rock or the Meteor Crater rock,” Rankin noted. “So, while impact effects would be more localized than regional, it certainly has the potential to do serious damage to the area it hits.”
On the other hand, if 2024 YR4 is an iron-rich asteroid, it could survive atmospheric entry and create a large impact crater, much like the one found in Arizona’s Meteor Crater, which was caused by an iron asteroid about 160 feet wide. “If made of iron, it will punch right through the atmosphere with little trouble and make an impact crater,” Rankin warned. “This is why understanding not just the orbit but also the composition and size are so critical.”
Key Details About Asteroid 2024 YR4
| Feature | Details |
|---|---|
| Estimated Size | 196 feet (60 meters) |
| Closest Approach | December 22, 2032 |
| Current Distance | 27 million miles from Earth |
| Chance of Impact | 1 in 83 (subject to revision with new data) |
| Potential Impact Corridor | South America to sub-Saharan Africa |
| Possible Effects | Airburst explosion or impact crater, depending on composition |
When Will We Know More?
While 2024 YR4 remains a subject of intense observation, astronomers acknowledge that definitive answers may not come until 2028, when the asteroid will make a closer pass within 5 million miles of Earth. This event will provide a critical opportunity for radar observations, helping scientists determine the asteroid’s exact size, shape, and composition.
“We will have the opportunity to continue to track this rock through February with 8-meter class telescopes, which we plan on doing at Catalina Sky Survey,” Rankin explained. “It is possible that even after February, we will not know for sure if it will hit or miss in 2032. We should be able to determine that better by 2028, when it should be visible again.”
These upcoming observations will either confirm the asteroid’s potential risk or eliminate it entirely, providing much-needed clarity on its fate.
A Reminder of Earth’s Vulnerability
While the most likely scenario remains a close flyby rather than an impact, the case of 2024 YR4 is a stark reminder that Earth is not immune to cosmic threats. Over the past century, asteroid impacts have caused localized destruction, such as the Tunguska event in 1908 and the Chelyabinsk airburst in 2013, which injured 1,500 people. Although large-scale extinction-level events are rare, even a small-to-medium-sized impact in a populated area could have serious consequences.
This is why planetary defense remains a global priority. Space agencies like NASA and ESA continue to develop early detection systems and impact mitigation strategies, such as the DART mission, which successfully altered an asteroid’s trajectory in 2022. Should 2024 YR4 be confirmed as a real threat, similar deflection technologies could be explored.
For now, astronomers continue to monitor the asteroid’s path, refining their predictions and ensuring that if action is needed, humanity will be ready.
