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Left to right: Asteroid Bennu, Fireball Meteor over Groningen, and Comet 67P Credits: Bennu: NASA, Meteor: Robert Mikaelyan, Comet 67P: ESA

Asteroids, Comets, Meteors, and Meteorites

A compilation of educational materials about asteroids, comets, meteors, and meteorites including resources for Asteroid Day, meteor showers, and links to NASA missions such as Lucy, OSIRIS-Rex, Psyche, Double Asteroid Redirection Test (DART), and Near-Earth Asteroid Scout (NEA Scout).
meteor poster from American Meteor Society
Download this American Meteor Society poster comparing comets, asteroids, and meteorites.

What is the difference?

  • An asteroid is a rocky object that orbits the Sun. Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. 
  • Comets are small icy dirtballs that orbit the Sun; comets are made of ice and dust while asteroids are made of rock).
  • A meteor is a space rock—or meteoroid—that enters Earth's atmosphere, as it – burns up upon entering Earth’s atmosphere, it creating a streak of light in the sky (often called "shooting stars"). When Earth encounters many meteoroids at once, we call it a meteor shower.
  • If a meteoroid survives its trip through Earth’s atmosphere and lands on the Earth’s surface, it is called a meteorite.

Banner images above, left to right:
Asteroid Bennu (NASA),
Fireball Meteor over Groningen the Netherlands (Robert Mikaelyan), and Comet 67P (ESA)


Now Discover all Our Near-Earth Object Asteroids and Comets using NASA Eyes.

Eyes on Asteroids cover image v2

Through the NASA’s Eyes on Asteroids visualization tool, you can now explore the asteroids and comets that approach Earth’s orbital neighborhood – and the spacecraft that visit these objects – with a click or a swipe. Thousands of asteroids and dozens of comets are discovered every single year, some of which – called near-Earth objects (NEOs) – follow orbits that pass through the inner solar system. With their numbers rising daily, these objects are tracked carefully by NASA-funded astronomers in case any might pose an impact threat to our planet. The daily-updated Eyes on Asteroids depicts the orbits of every known NEO, providing detailed information on those objects. Using the slider at the bottom of the screen, you can travel quickly forward and backward through time to see their orbital motions.


Annual Events

Asteroid Day logo June 30th

Asteroid Day


Perseid Meteor Shower - a meteor streaks across the sky 2016 in Spruce Knob West Virginia Credit NASA Bill Ingalls
A meteor streaks across the sky
during the Perseid Meteor Shower in Spruce Knob West Virginia 2016,
credit: NASA /Bill Ingalls

Perseid Meteor Shower

The Perseids are the most popular meteor shower as they peak on warm August nights as seen from the northern hemisphere. Check the astronomical events calendar below.


screenshot of the astromaterials meteorite viewer

NASA Resources

an artistic depiction of NASA OSIRIS-REx mission
Artistic depiction of OSIRIS-Rex mission

Featured NASA Missions and Programs




NASA Asteroid Watch

Near-Earth Asteroid Scout (NEA Scout) 

Double Asteroid Redirection Test (DART)

Hayabusa2 Mission

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