Astronomers poring over the treasure trove of data from the James Webb Space Telescope (JWST) have made a groundbreaking discovery. More than 100 previously unseen asteroids, some smaller than a school bus, have been detected zipping through the asteroid belt between Mars and Jupiter. And here’s the kicker: a few of them appear to be on a trajectory that brings them uncomfortably close to Earth.
This discovery isn’t just a feather in JWST’s cap; it’s a paradigm shift in how we track space rocks that could pose a threat.
Small Asteroids, Big Impact
Let’s not underestimate these pint-sized asteroids. While they’re nowhere near the size of the one that wiped out the dinosaurs, even a rock a few tens of meters wide can pack a wallop. Remember the Chelyabinsk event in 2013? A 20-meter-wide asteroid exploded over Russia with 30 times the energy of the Hiroshima bomb, shattering windows across six cities and injuring over 1,500 people.
Now imagine finding hundreds of these lurking in our cosmic neighborhood. That’s exactly what Julien de Wit, an MIT planetary scientist, and his team uncovered when they analyzed 93 hours of JWST images of the TRAPPIST-1 system, a stellar family about 40 light-years away.
A Revolutionary Technique
What sets this discovery apart is the cutting-edge method the team used. Normally, spotting asteroids requires knowing their orbits ahead of time, but this approach broke the mold. By harnessing the brute computational power of GPUs, the researchers performed a “blind search” across thousands of images, stacking them to tease out faint, fast-moving objects.
Their efforts unearthed 138 new “decameter” asteroids—so named because they measure just tens of meters across. Six of these are now confirmed to have been nudged by gravitational forces into paths that bring them perilously close to Earth.
Why JWST Is Perfect for the Job
JWST’s infrared capabilities are the real hero here. Unlike visible-light telescopes, which rely on sunlight bouncing off an asteroid’s surface, JWST detects the heat these rocks emit. This makes it far more effective at spotting smaller, colder, and darker objects that traditional surveys miss.
And the best part? JWST isn’t done yet. Future observations are set to target at least 20 distant stars over 500 hours, a move researchers expect could reveal thousands more of these elusive space rocks.
The Next Frontier: Vera Rubin Observatory
But JWST won’t be working alone. Starting next year, the Vera C. Rubin Observatory in Chile is set to join the asteroid hunt. Armed with the largest digital camera ever built, it will photograph the southern sky every night for a decade. Each image will cover an area equivalent to 40 full moons, with a resolution sharp enough to catalog up to 2.4 million asteroids in just six months.
This one-two punch of JWST and Rubin’s observatory marks a new era in planetary defense. With advanced tracking capabilities, scientists can now monitor these small asteroids long before they get close enough to cause trouble.
As study co-author Artem Burdanov put it, “We’re entering a completely unexplored space, thanks to modern technologies.” It’s a big payoff for a field that thrives on pushing boundaries, and one that might just keep us safe from the next Chelyabinsk-style surprise.
