James Webb Telescope Spots 138 New Asteroids in the Main Belt, Some Heading Towards Earth

Astronomers have identified a significant population of previously undetected asteroids in the main belt between Mars and Jupiter, according to research published on December 9, 2024, in Nature. This discovery was made through analysis of archival images from the James Webb Space Telescope (JWST). Among these asteroids, some have been found on trajectories that could bring them close to Earth, as per the findings. The detected asteroids, ranging from the size of a bus to that of multiple stadiums, represent the smallest known objects within the main asteroid belt.

Although smaller than the asteroid linked to the extinction of the dinosaurs, these space rocks carry potential risks due to their capacity for destruction. For instance, a decametre-sized asteroid exploded above Chelyabinsk, Russia, a decade ago, releasing energy equivalent to 30 Hiroshima bombs.

A Computational Breakthrough in Asteroid Detection

As per reports, Julien de Wit, Associate Professor of Planetary Science at MIT, and his team have employed a computationally intensive technique to identify these space rocks. The approach, applied to JWST images originally focused on the TRAPPIST-1 system, allowed for the discovery of 138 new asteroids. Six of these appear to have been influenced by planetary gravitational forces, potentially positioning them near Earth in the future. De Wit described the unexpected volume of detections as indicative of a "new population regime".

Advantages of Infrared Detection

The telescope's infrared capabilities were key to this achievement, as they captured thermal emissions from the asteroids more effectively than traditional visible-light methods. Artem Burdanov, a research scientist at MIT, noted this as an example of how revisiting data with modern technology can yield substantial discoveries.

Upcoming observations using JWST and other telescopes, such as the Vera C. Rubin Observatory, are expected to identify thousands more small asteroids, advancing planetary defence and orbital tracking.