On December 20, 2024, NASA announced the discovery of over 100 new asteroids in the main asteroid belt between Mars and Jupiter using the James Webb Space Telescope (JWST). This discovery includes the smallest asteroids ever identified, previously undetectable by ground-based telescopes.
The research team from the Massachusetts Institute of Technology (MIT) observed 138 new asteroids, ranging in size from that of a bus to a sports stadium. This marks the first time such small asteroids have been observed in the main asteroid belt.
Understanding the variety of asteroid sizes in the main belt can provide insights into how asteroids evolve over time due to collisions, which relates to the history of the solar system and the mechanisms that allow some asteroids to escape the belt, potentially leading to meteorite impacts on Earth.
Tom Greene, an astrophysicist at NASA's Ames Research Center, noted that this research enhances knowledge about the formation and quantity of smaller celestial bodies in the main asteroid belt. He indicated that these smaller asteroids might be remnants of collisions between larger asteroids.
Jessie Dotson, also from Ames, emphasized the significance of JWST's capabilities in gathering asteroid-related data, stating that understanding the size, quantity, and evolutionary history of smaller asteroids could provide crucial context for near-Earth asteroid research and planetary defense.
The research team developed a method to analyze existing JWST images for the presence of asteroids, which may have been inadvertently captured while observing the star TRAPPIST-1. The images, initially aimed at searching for exoplanet atmospheres, revealed that asteroids appear brighter in infrared light, aiding the detection of previously unknown asteroids in the main belt.
Nasa plans to utilize infrared technology in its upcoming Near-Earth Object Surveillance Mission, which will be the first space telescope specifically designed to identify potentially hazardous near-Earth asteroids and comets.
The findings were published in the journal Nature on December 9, 2024.