Webb Telescope Uncovers 138 Elusive New Asteroids in Cosmic Hunt

Referring to something as being the scale of a stadium might suggest it is vast, yet concerning the vastness of our Solar System, that’s merely a grain of sand.

The James Webb Space Telescope has empowered astronomers to identify the smallest asteroids ever recognized in the principal asteroid belt situated between Mars and Jupiter.

It has identified 138 new asteroids within the belt, varying from the size of a stadium down to as tiny as a bus.

Astronomers assert that this size spectrum has never been detectable through ground-based telescopes, showcasing the capabilities of the James Webb Space Telescope.

The finding

The asteroid belt represents a ring of celestial rocks orbiting the Sun, positioned between the paths of Mars and Jupiter.

It is probably composed of materials that were leftovers from the emergence of our Sun: the very materials from which the planets were created.

Consequently, asteroids are ancient remnants of the early Solar System, offering significant insights into its formation and evolution.

This recent finding was accomplished by a research group spearheaded by scientists from the Massachusetts Institute of Technology (MIT).

They repurposed Webb’s observations of a remote star to uncover a collection of small asteroids.

These represent the tiniest ever identified within the main asteroid belt.

Their diminutive size aids scientists in constructing a more precise representation of the diversity of asteroids in the belt, as well as how they have transformed over time through collisions.

“We now grasp more about the formation of smaller entities in the asteroid belt and the potential quantity of such objects,” states Tom Greene, astrophysicist at NASA’s Ames Research Center in California’s Silicon Valley and co-author of the research.

“Asteroids of this dimension likely emerged from collisions involving larger asteroids in the main belt and are prone to drift toward the neighborhood of Earth and the Sun.”

Safeguarding Earth

The findings could prove particularly beneficial to the Asteroid Threat Assessment Project at Ames.

ATAP aids NASA’s Planetary Defense Coordination Office by examining the potential impacts of a large asteroid collision with Earth.

“It’s thrilling that Webb’s capabilities can be utilized to extract knowledge about asteroids,” remarks Jessie Dotson, astrophysicist at Ames and part of ATAP.

“Gaining insights into the dimensions, quantities, and developmental history of smaller main belt asteroids provides critical context regarding the near-Earth asteroids we investigate for planetary defense.”

Captured on camera

The recently identified minuscule asteroids were discovered by scrutinizing existing images from the James Webb Space Telescope.

The research team, directed by Artem Burdanov and Julien de Wit, both from MIT, devised a technique to identify asteroids that may have been inadvertently captured by Webb’s imaging.

By employing a processing method, they analyzed over 10,000 images of the star TRAPPIST-1, originally taken to investigate atmospheres surrounding planets orbiting that star.

Asteroids emit strong infrared light, which is the wavelength Webb is specialized to detect.

As a result, they were able to reveal a collective of small asteroids that had gone undetected until this point.

The research was discussed in a paper titled Detections of decameter main-belt asteroids with JWST presented on 9 December 2024 in Nature.