Space rock 2024 YR4 still has 2.4% shot at smacking Earth
The latest figures from the European Space Agency (ESA) on the trajectory of asteroid 2024 YR4 show a reduction in uncertainty around the object’s orbit while the probability of impact remains low.
The estimates from ESA’s Near-Earth Object Coordination Centre show a marked reduction in close approach uncertainty based on observations made up to February 17.
The probability of Earth impact remains at 2.4 percent, and the estimated size of the asteroid is still anywhere from 40 to 90 meters. However, the close approach uncertainty – a range of trajectories that the asteroid could be on – has narrowed as observations continue.
The Earth remains in the risk corridor for now, but as uncertainty is whittled away, the probability of impact will likely eventually decrease and reach zero, although it might initially grow as the corridor narrows.
Plot showing how close asteroid 2024 YR4 will get to Earth in 2032 (Credit: ESA/Planetary Defence Office) – click to enlarge
The reduction in the range of close approach uncertainty is an example of how scientists are using observations to refine their calculations, even as asteroid 2024 YR4 remains at a safe distance. However, it is not yet possible to rule out all risk, although the data expected to start rolling in from the James Webb Space Telescope (JWST) will further refine estimates.
Risk corridor for asteroid 2024 YR4 on December 22, 2032, using data from observations made up to February 17, 2025 (Credit: ESA/Planetary Defence Office) – click to enlarge
The asteroid will eventually fade from view, and it is likely to remain on the risk list until it becomes observable again in 2028. However, the uncertainty chart is a clear indicator that the science is working. The Earth is still in the risk corridor for the asteroid, but that corridor is narrowing. Eventually, the corridor might narrow to the point where the Earth is excluded. ®
