Asteroids are rocky small bodies that orbit the Sun in a wide band, known as the asteroid belt, between the orbits of Mars and Jupiter. Asteroids come in all shapes and size, and they are also referred to as minor planets.

Over the course of history, astronomers have discovered hundreds of thousands of asteroids, and they believe millions of boulder-sized asteroidal fragments are out there in the solar system. But, have you ever given a thought on how astronomers discovered these bits of rock and metal? How many they have found? And how they tell asteroids apart?

Here, Carrie Nugent from TED-Ed shares the story of the very first asteroid ever discovered (Ceres) and explains how asteroid hunters search for these celestial bodies.