Potentially Hazardous Asteroid 2024 YR4: James Webb Telescope Deployed
James Webb Telescope to Provide Clarity
The James Webb Space Telescope will soon observe near-Earth asteroid 2024 YR4 in the infrared spectrum to obtain more precise data on its size and orbit. This step, announced by the European Space Agency (ESA), comes after 375 ground-based observations failed to rule out a possible collision in about eight years. Current estimates range between 40 and 90 meters in diameter, creating a wide range of potential outcomes should an impact occur.
Impact Still Highly Unlikely
According to the ESA, there is presently a 2% chance that 2024 YR4 could strike Earth—meaning a 98% likelihood that it will miss us. Any collision would likely produce only local or regional damage, depending on the asteroid’s actual size. Even so, the possible risks demand attention from planetary defense experts who must work with limited data. Because ground-based observations only approximate size via reflectivity, the object may be smaller but more reflective, or larger and darker.
Why James Webb?
By viewing 2024 YR4 in the infrared range, Webb can detect the asteroid’s thermal emissions, enabling a far more accurate measure of its diameter. ESA plans two observation windows: one in early March and another in May. These scans will not only track changes in thermal output but also refine orbit calculations before 2024 YR4 becomes unobservable for several years. This campaign uses specially reserved “rapid-response” observation time dedicated to urgent scientific needs.
Elevated Risk Compared to Recent History
Discovered on December 27 using a Chilean telescope, 2024 YR4 quickly soared to the top of ESA’s and NASA’s lists of hazardous near-Earth objects. Observations indicate an impact on December 22, 2032 cannot yet be discounted. Prior to the weekend, the projected risk climbed as high as 2.3%, though it has since dipped slightly. Most experts still anticipate the probability will diminish further—historically, similar objects were eventually shown to pose no real threat.
On the Torino Scale (a system for classifying asteroid impact risks), 2024 YR4 currently sits at Level 3, making it the most potentially dangerous new object identified in recent years. Only one other asteroid, (99942) Apophis, once reached Level 4 and has since been downgraded to no risk. Level 3 status indicates both public and official attention are warranted.
International Response in Motion
Two United Nations–recognized organizations have already engaged with the potential threat from 2024 YR4:
- International Asteroid Warning Network (IAWN), coordinated by NASA.
- Space Mission Planning Advisory Group (SMPAG), operating under ESA.
These groups recently met to discuss 2024 YR4, deciding to continue observation and assessment. While possible defense measures have been informally raised, experts caution that it’s too early for definitive plans. Should May’s upcoming observations fail to eliminate all risk for 2032, the situation will be revisited for new action steps.