The James Webb Space Telescope (JWST) has discovered tiny asteroids in the asteroid belt between Mars and Jupiter. Using its advanced infrared capabilities, JWST identified asteroids as small as 100 meters in diameter, shedding new light on the early solar system. This breakthrough allows scientists to study these objects, offering insights into planetary formation and solar system dynamics.
NASA’s James Webb Space Telescope continues to demonstrate its exceptional versatility, now contributing valuable insights into the study of asteroids. Known primarily for its observations of distant galaxies, stars, and exoplanets, the Webb telescope also delves into the mysteries of objects closer to home, including the main asteroid belt located between Mars and Jupiter.
In an innovative approach, a research team led by scientists from the Massachusetts Institute of Technology (MIT) in Cambridge repurposed Webb’s observations of a distant star to uncover an unprecedented population of small asteroids. These celestial objects, ranging from the size of a bus to a stadium, represent the smallest asteroids yet observed in the main belt. Their discovery highlights Webb’s capacity to detect objects that were previously invisible to ground-based telescopes due to their diminutive size.
The study identified 138 new asteroids within this size range, offering astronomers a unique opportunity to understand the dynamics and evolution of the main asteroid belt. By analyzing the distribution and size ranges of these asteroids, researchers gain crucial insights into the processes that shape their formation and evolution. One key aspect is how collisions between larger asteroids generate smaller fragments, which may eventually drift toward Earth and the Sun over billions of years.
According to Tom Greene, an astrophysicist at NASA’s Ames Research Center in California and a co-author of the study, these findings shed light on the origins and behavior of small asteroids. “Asteroids this size likely formed from collisions between larger ones in the main belt and are likely to drift towards the vicinity of Earth and the Sun,” Greene explained. This knowledge is not only valuable for understanding the history of the asteroid belt but also has implications for planetary defense.
NASA’s Asteroid Threat Assessment Project (ATAP) at Ames benefits directly from these discoveries. ATAP supports the Planetary Defense Coordination Office by evaluating potential asteroid impact scenarios and modeling associated risks. Small main belt asteroids, like those identified in the study, could eventually migrate into near-Earth space. Understanding their sizes, distributions, and evolutionary pathways provides essential context for assessing the threat they may pose.
Jessie Dotson, an astrophysicist at Ames and a member of ATAP, emphasized the significance of Webb’s findings for planetary defense. “It’s exciting that Webb’s capabilities can be used to glean insights into asteroids,” Dotson remarked. “Understanding the sizes, numbers, and evolutionary history of smaller main belt asteroids provides important background about the near-Earth asteroids we study for planetary defense.”
This groundbreaking research not only expands our knowledge of the main asteroid belt but also reinforces the Webb telescope’s role as a critical tool in protecting Earth. Its ability to detect and analyze previously unseen celestial objects ensures that we can continue to refine our understanding of the solar system and enhance strategies for planetary defense.
A groundbreaking discovery led by a team from the Massachusetts Institute of Technology (MIT) showcases the extraordinary versatility of NASA’s James Webb Space Telescope. By analyzing images originally intended for entirely different purposes, the team uncovered a hidden population of small asteroids in the main asteroid belt. The team, led by research scientist Artem Burdanov and planetary science professor Julien de Wit, both of MIT, devised an innovative image-processing method to detect these asteroids.
The approach leveraged over 10,000 existing Webb images of the star TRAPPIST-1. These images were initially captured as part of efforts to study the atmospheres of planets orbiting the star, with the ultimate goal of searching for life beyond Earth. However, by repurposing this data, the team revealed a wealth of previously undetected main belt asteroids that had inadvertently been “caught on film” as they moved across Webb’s field of view.
The infrared capabilities of the Webb telescope played a crucial role in these detections. Asteroids emit more light in the infrared spectrum than in visible light, making them stand out in Webb’s observations. This inherent glow in the infrared spectrum enabled the identification of asteroids as small as a few tens of meters across—a size range that was previously unobservable with ground-based telescopes. This discovery represents a significant step forward in our understanding of the main asteroid belt and its composition.
NASA’s upcoming Near-Earth Object (NEO) Surveyor mission will also capitalize on the benefits of infrared light. As the first space telescope specifically designed to search for near-Earth asteroids and comets, the NEO Surveyor will build on Webb’s capabilities to hunt for potential hazards to Earth. The mission will identify and track objects that could pose a threat, contributing to planetary defense efforts.
The findings of the MIT-led research were published on December 9 in the prestigious journal Nature, in a paper titled “Detections of decameter main-belt asteroids with JWST.” The study demonstrates how data gathered for one scientific purpose can yield unexpected discoveries when approached with ingenuity and novel techniques.
The James Webb Space Telescope continues to be a transformative tool for science, demonstrating unparalleled versatility. While its primary objectives include probing distant galaxies, unraveling the mysteries of exoplanets, and exploring the origins of the universe, Webb has now also proven instrumental in advancing our understanding of objects closer to home. These include small asteroids within our solar system, which provide valuable insights into planetary formation and evolution.
Webb is the world’s premier space science observatory, an international collaboration led by NASA with support from the European Space Agency (ESA) and the Canadian Space Agency (CSA). Its ability to address diverse scientific questions—from understanding the population of main belt asteroids to searching for habitable worlds around other stars—underscores its transformative role in shaping the future of space exploration.
( Source: NASA )