NASA Calls in Webb Telescope to Track Recently Identified Hazardous Asteroid

Faced with the (very low probability) threat of an incoming asteroid impact, NASA is bringing out the big guns. The agency will employ its powerful Webb space telescope to monitor newly discovered asteroid 2024 YR4, which has a small chance of hitting Earth in 2032.

Based on current estimates, asteroid 2024 YR4 has a 2.1% chance of impact on December 22, 2032. Although the odds are still in our favor, there are currently no other known large asteroids with an impact probability above 1%, according to NASA. The space agency tends to take these matters quite seriously, which is why it plans to collect additional observations of the space rock using the Webb telescope in March to refine the current estimates, NASA revealed in a recent update.

The Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile discovered the asteroid on December 27, 2024. Shortly after its discovery, the impact probability of the asteroid was set to 1.3%. However, additional observations increased the asteroid’s chances of crashing into Earth to 2.3% as of yesterday, before dropping slightly to 2.1% this morning. These odds are preliminary, and more observations of the asteroid are desperately needed.

When it was first spotted, asteroid 2024 YR4 was 515,116 miles (829,000 kilometers) away from Earth. Unfortunately, the space rock is moving away from us and its next close approach won’t be until December 2028. Ground-based telescopes in the International Asteroid Warning Network are currently tracking the asteroid and will continue through April. After that, it will be too faint to observe until June 2028, according to NASA. That’s why Webb will be stepping in, capturing the asteroid from space.

Using Webb’s observations, astronomers are hoping to get a better estimate of the asteroid’s size, among many other variables Based on current estimates from its reflected light, the asteroid measures between 130 and 300 feet wide (40 and 90 meters). It’s not large enough to cause total annihilation, but its unlikely impact would release about 8 megatons of energy—more than 500 times the energy released by the atomic bomb dropped on Hiroshima in 1945, and comparable to the energy released in the Tunguska blast of 1908, according to NASA.

NASA deems any asteroid as potentially hazardous if it is between 100 and 165 (30 and 50 meters) in diameter and if its orbit brings it within 5 million miles (8 million kilometers) of Earth’s orbit. Asteroid 2024 YR4 rose to the top of NASA’s Sentry risk list, which includes any known near-Earth asteroids that have a non-zero probability of impacting Earth in the future. It’s currently the only known asteroid ranked a 3 on the Torino Impact Hazard Scale), which NASA defines as “Meriting Attention by Astronomers.”

Several objects in history have climbed the risk list, only to drop off once new data became available, NASA explained in the update, adding: “New observations may result in reassignment of this asteroid to 0 as more data come in. ” Well, let’s hope so.