**PASADENA, California** — The recently identified asteroid, known as 2024 YR4, currently has an estimated 2% chance of colliding with Earth in 2032. While these odds are quite low, astronomers are diligently monitoring this celestial body to gather more information, a task that could soon leverage the capabilities of the most advanced observatory ever sent into space.

Although details about 2024 YR4 are limited, scientists estimate its diameter to range between 131 and 295 feet, which is comparable to the height of a large building, as noted by Dr. Paul Chodas, the manager of NASA’s Near-Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory in Pasadena, California.

In contrast, this size is minuscule compared to the “planet-killer” asteroid that impacted Earth 66 million years ago, leading to the extinction of the dinosaurs. That asteroid, which was about 6.2 miles wide, is the last significant asteroid known to have struck our planet. “Planet killer” asteroids are defined as those larger than one kilometer and could have catastrophic impacts on life.

However, even smaller asteroids like 2024 YR4 can cause considerable damage regionally if they are found to be on a collision path with Earth. For this reason, astronomers are eager to gather as much knowledge about 2024 YR4 as quickly as possible.

By refining the asteroid’s trajectory and gathering more data, scientists aim to eliminate the possibility of an impact entirely. However, time is running short, as astronomers must observe 2024 YR4 before it becomes less visible in April. To aid in this effort, the James Webb Space Telescope plans to focus on 2024 YR4 to better determine its size and orbit.

Monitoring a Potential Threat from Space

The Asteroid Terrestrial-impact Last Alert System (ATLAS) in Rio Hurtado, Chile, was the first to detect asteroid 2024 YR4 on December 27. ATLAS is part of NASA’s initiative to locate near-Earth asteroids, as explained by Davide Farnocchia, a navigation engineer at JPL and CNEOS.

Despite numerous observations from various telescopes, the size estimate for 2024 YR4 has remained relatively stable; this is due to the challenge of studying the asteroid, as its size is primarily determined by the sunlight it reflects. The reflected light helps astronomers gauge its size.

Since early January, astronomers have utilized the Magdalena Ridge Observatory in New Mexico, the Danish Telescope, and the Very Large Telescope in Chile to track the asteroid, which is currently positioned over 30 million miles away from Earth and continuing to drift farther, according to Farnocchia.

Observatories in Hawaii are also involved in the monitoring process. The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), situated on the Haleakalā volcano in Maui, leads the world in discovering near-Earth objects. It is currently assisting in tracking the movements of 2024 YR4 from a distance.

If asteroid 2024 YR4 becomes invisible before scientists can dispel any fears of impact, it will remain on the risk list until it reappears in June 2028. Projections of the asteroid’s orbit suggest it returns near Earth every four years, but it is not expected to present a threat during its 2028 pass, as reported by the University of Hawaii.

Evaluating Impact Risks

Determining the precise size of the asteroid could be critical in assessing the risks should 2024 YR4 be found on a potential collision trajectory.

Dr. Chodas elaborated, “If the asteroid is on the larger end of its estimated size, an impact could cause blast effects extending up to 31 miles from the point of impact.” This scenario, however, remains highly unlikely. The asteroid would enter the atmosphere at an incredibly high speed—approximately 38,028 miles per hour—which could result in significant damage.

According to the European Space Agency, asteroids of this magnitude typically strike Earth every few thousand years and can create severe local destruction.

For instance, in 1908, a 98-foot-wide asteroid impacted the remote region of the Podkamennaya Tunguska River in Siberia, leveling trees over an 830-square-mile area.

Similarly, in 2013, a 66-foot-wide asteroid entered Earth’s atmosphere over Chelyabinsk, Russia, detonating in a massive explosion that released energy far exceeding that of the first atomic bomb. This event produced light brighter than the sun and caused damage to over 7,000 buildings, injuring more than 1,000 individuals.

However, the ramifications of 2024 YR4 could be much graver if it is indeed larger, as suggested by the European Space Agency.

Each year, roughly 3,000 new near-Earth objects are cataloged; however, finding asteroids within 2024 YR4’s size range is more challenging since they are often smaller, darker, and harder to detect through telescopes. Scientists believe there are around 600,000 rocky bodies of similar size, yet only about 2%—or approximately 12,000—have been discovered to date, according to the European Space Agency.

As explained by Dr. Larry Denneau, an astronomer at the University of Hawaii’s Institute for Astronomy and co-principal investigator at the ATLAS telescope, “Although small asteroids frequently impact Earth, they disintegrate in the atmosphere and generally cause minimal ground damage. Larger asteroids can result in significant destruction, but they occur less often. Numerous larger asteroids are still out there yet to be detected, which necessitates continuous sky monitoring to preemptively address any potential threats.”