In December of 2024, an asteroid named YR4 2024 had, according to The New York Times, become the “most likely sizable space rock ever forecast to impact planet Earth.” Ranging in probable diameters from 130 feet to 300 feet, it is expected to either collide with Earth or make an extremely close pass in 2032. NASA has raised the probability of asteroid 2024 YR4 striking Earth in seven years from 1.2% to 2.3%. The chances then increased to 2.6% and have now reached 3.1%, according to the latest data from NASA’s Center for Near Earth Object Studies.

Although YR4’s size makes it unlikely to destroy a country, with a direct hit, it would likely decimate a city in a single blow. Fortunately, the estimated route is over open ocean, substantially reducing the potential damage; an asteroid of that magnitude also would not trigger a huge, destructive tsunami or any other calamities if it were to land over open water, far from shore. According to The New York Times, nearby cities include Bogotá, Lagos and Mumbai. 

Since asteroids generally move at the same speed (38,000 miles per hour), mass and material have a significant impact on the extent of damage of collisions. An iron-based asteroid would be more likely to penetrate Earth’s atmosphere and strike the planet directly. According to NASA, YR4 is being studied as a stony asteroid, meaning it is made of rock material and would be more likely to break up into fragmented pieces when heated.

A valid comparison point, according to the Royal Museums Greenwich, would be the Tunguska event in 1908, which involved a stony asteroid similar in size to YR4 2024. It exploded over a remote area in Siberia, generating a blast wave that wiped out a forest more than twice the size of New York City. In contrast, people and buildings would be in danger if YR4 were to implode directly above a city. “Windows would explode inward, producing shotgun sprays of glass, and the damage to buildings would be widespread,” The New York Times reported. There would  even be some fatal injuries. 

Because of its size and composition, YR4 has a higher chance of passing through Earth’s atmosphere undamaged and landing a hit due to its steep landing angle. In this instance, it would emit a blast of hot asteroid vapor and create a crater that is over two-thirds of a mile wide if it landed on land. Researchers estimate that everything within a twenty-mile radius, including nature and buildings, would be severely impacted, and that those living close to ground zero would probably perish.

While the likelihood of impact remains small, YR4’s approach has captured the attention of scientists and researchers worldwide. As new information becomes available, researchers keep improving trajectory models and evaluating possible hazards. For the time being, experts stress the importance of ongoing surveillance, but mitigating methods may also be explored if the likelihood of a collision increases.