In late December, astronomers using the Asteroid Terrestrial-Impact Last Alert System (ATLAS) telescope in Chile discovered a new asteroid near our planet. Known as 2024 YR4, this object is estimated to be between 40 and 100 meters in size and was first sighted on December 27. YR4 had its closest encounter with Earth two days earlier, when it was approximately 800,000 kilometers away from our planet, about twice the distance to the moon. John Tonry, an astronomer at the University of Hawaii, described it as “zooming right by Earth.” While asteroids of this size are not uncommon in our solar system, the potential risk posed by this one prompted further investigation.
Contrary to ruling out an impact, follow-up observations have raised concerns. On January 27, NASA’s Sentry service upgraded the risk of Y24 impact on Earth to an unprecedented level of 1.3 percent for December 22, 2032. This assessment corresponds to a threat level of 3 on the Torino scale. The European Space Agency (ESA) also estimated a similar impact risk, and NASA’s Sentry service later increased the risk to 1.6 percent.
While the chance of an impact remains low, the potential consequences of an impact by an asteroid the size of YR4 would be devastating. This stony asteroid, if it were to collide with Earth, could cause widespread regional destruction, similar to the Tunguska event in 1908 or the Chelyabinsk meteor in 2013. Despite the low probability of impact, the ongoing analysis suggests a need for preparedness and caution.
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As astronomers continue to monitor YR4, there is a growing concern about its potential impact trajectory. The estimated impact corridor ranges from the Pacific Ocean through various continents, highlighting the need for vigilance and preparedness.
The urgency of the situation is underscored by the limited visibility window for telescopic observations of the asteroid. Time is of the essence, with the next opportunity for close observation not expected until 2028. Contingency plans, including possible deflection missions or evacuation measures, are being considered in case the impact risk escalates.
