NASA has updated its impact probability for 2024 YR4, raising its 2032 chance of colliding with Earth to 2.3% from 1.9%. That update generated a lot of buzz, but astronomers say continued observations will most likely narrow down such estimates and make them less of an issue.
Asteroid 2024 YR4 was first spotted on December 27, 2024, at the ATLAS telescope in Chile, under the Asteroid Terrestrial-impact Last Alert System. It was confirmed at first to be a Near-Earth Object (NEO) when its path was calculated to have it near our planet. NASA and the European Space Agency have kept a close eye on its path ever since its discovery, using high-tech tracking technology to predict its future path.
The most current estimates have placed the odds of impact at 1.9% and then 2.3%, approximately a 1 in 43 chance of a December 22, 2032, collision. That is a significant rise, but hardly a near certainty. Historically, such early estimates have regularly been reduced when additional information comes in. For instance, 99942 Apophis, a one-time danger, later was determined to be safe for at least a hundred years following additional observations.
Asteroid 2024 YR4 is 40 to 90 meters (130 to 300 feet) in diameter and traveling at an astonishing 29,000 miles per hour (46,800 km/h). Were it to collide with our planet, it would cause localized destruction similar to that of the 1908 Tunguska explosion, which cleared over 2,150 square kilometers (830 square miles) of Siberian woodland. It is not large enough to cause a worldwide disaster but will deliver enough impact energy to destroy a city, a district, and even a metropolitan region with ease.
NASA and the European Space Agency monitor 2024 YR4 closely, with follow-up observations in April 2025 with the James Webb Space Telescope. Those observations will allow astronomers to precisely narrow down the path of the asteroid and to continue updating the impact probability. In similar situations in the past, further observations have typically caused risk estimates to decrease to almost zero as more accurate calculations are made.
Should the peril continue, a range of planet-saving alternatives will be at the disposal of space agencies:
Kinetic Impactor: Spacecraft can deliberately impact an asteroid in a manner that deflects its path, for instance, in 2022’s successful Double Asteroid Redirection Test (DART) conducted by NASA.
Nuclear Deflection: Detonating a nuclear weapon near an asteroid can deflect its path, but such a move is yet to become acceptable.
Laser Ablation: High-powered laser can vaporise parts of the asteroid, creating a thrust to deflect its path.
Gravity Tractors: Spacecraft can follow an asteroid for a long period, using its gravity to gently deflect an asteroid’s path. Despite an increased level of danger, professionals have urged citizens not to worry.
NASA’s Office for Planetary Defense emphasized that a lot of asteroids initially considered a threat have later not posed a threat at all. On a 10-step (global disaster) to 0 (no threat at all) Torino Impact Hazard Scale, 2024 YR4 ranked 3, meaning that it is a cause for concern but not at present a cause for alarm.
