Astronomers used james webb telescope data to discover tiny main-belt asteroids, improving asteroid tracking and planetary defense.

Until now, only objects with a diameter of at least several hundred meters were known in the asteroid belt; most of them were too small. This is changing.

The majority of the known asteroids orbit within the main asteroid belt located between Mars and Jupiter at an average distance from Earth of about

The asteroid that extinguished the dinosaurs is estimated to have been about 10 kilometers across. That's about as wide as Brooklyn. Such a massive impactor is predicted to hit Earth rarely, once every 100 million to 500 million years.

MIT astronomers have found a way to spot the smallest, “decameter,” asteroids within the main asteroid belt. They used their approach to detect more than 100 new asteroids, ranging from the size of a bus to several stadiums wide,