Asteroid or Meteor: What's the Difference?

The Short Answer:

An asteroid is a small rocky object that orbits the Sun. Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. A meteor is what happens when a meteoroid – a small piece of an asteroid or comet – burns up upon entering Earth’s atmosphere, creating a streak of light in the sky.

An asteroid is a small rocky object that orbits the Sun. A meteor is what happens when a small piece of an asteroid or comet, called a meteoroid, burns up upon entering Earth’s atmosphere. Read on to find out more and learn the difference between asteroids and comets, meteoroids and meteorites, and more!

Asteroids

An asteroid is a small rocky body that orbits the Sun.

A close-up view of Eros, an asteroid with an orbit that takes it somewhat close to Earth. The photo was taken by NASA’s Near Earth Asteroid Rendezvous - Shoemaker spacecraft in 2000. Image credit: NASA/JHUAPL

Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. Most asteroids in our solar system are found in the main asteroid belt, a region between Mars and Jupiter. But they can also hang out in other locations around the solar system. For example, some asteroids orbit the Sun in a path that takes them near Earth.

Illustration of the location of the asteroid belt between Mars and Jupiter.

Most asteroids in our solar system can be found in the asteroid belt, between Mars and Jupiter.

Meteoroids

Sometimes one asteroid can smash into another. This can cause small pieces of the asteroid to break off. Those pieces are called meteoroids. Meteoroids can also come from comets.

Illustration of a large asteroid and a small meteoroid that has broken off of it.

Meteors

If a meteoroid comes close enough to Earth and enters Earth’s atmosphere, it vaporizes and turns into a meteor: a streak of light in the sky.

Because of their appearance, these streaks of light are sometimes called "shooting stars." But meteors are not actually stars.

A photograph of meteors streaking through the sky, taken during the Perseid meteor shower.

At certain times of the year, you might be lucky enough to see more meteors in the sky than usual. This is called a meteor shower. This photo was taken during the Perseid meteor shower, which happens each year in August. Image credit: NASA/JPL

Because meteors leave streaks of light in the sky, they are sometimes confused with comets. However, these two things are very different.

Comets

Comets orbit the Sun, like asteroids. But comets are made of ice and dust—not rock.

As a comet’s orbit takes it toward the Sun, the ice and dust begin to vaporize. That vaporized ice and dust become the comet’s tail. You can see a comet even when it is very far from Earth. However, when you see a meteor, it’s in our atmosphere.

Meteorites

Sometimes meteoroids don’t vaporize completely in the atmosphere. In fact, sometimes they survive their trip through Earth’s atmosphere and land on the Earth’s surface. When they land on Earth, they are called meteorites.

A photograph of a man walking towards a meteorite in Sudan's Nubian Desert.

A scientist investigates a meteorite that landed in Sudan's Nubian Desert in 2008. Image credit: NASA

NASA’s Johnson Space Center has a collection of meteorites that have been collected from many different locations on Earth. The collection acts as a meteorite library for scientists. By studying different types of meteorites, scientists can learn more about asteroids, planets and other parts of our solar system.

Because asteroids formed in the early days of our solar system nearly 4.6 billion years ago, meteorites can give scientists information about what the solar system was like way back then!