Now, an international team of astronomers has located more than 100 of these so-called “decameter” asteroids, named because they measure tens of meters in diameter, or roughly 30 to 1,600 feet across.

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

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.