Meteoroids are small objects, mostly smaller than an inch in diameter, which enter the Earth’s atmosphere at high speeds. They burn up completely when they reach the ground or hit the ocean surface.
Meteors are fragments of asteroids which have broken off and are entering the atmosphere at high speeds. The speed of a meteoroid is around 15-20 km/s and the speed of a meteor is between 110-300 km/s.
Asteroids are rocks that orbit around the Sun. Most asteroids have orbits that cross Earth’s orbit so they are known as near-Earth objects (NEO). NEOs do not orbit around any planet but can still cause significant damage to satellites, satellites in space, or even astronauts on board a spacecraft.
| Asteroid | Meteor |
| Rocks that orbit around the Sun. | Small particles that travel through space in orbit around the Sun. |
| Orbits in a stable ecosystem and can last for million years without being disturbed by other objects. | Does not orbit in stable orbits and instead falls into a chaotic area between the planets or stars. |
The moon has its own set of near-Earth objects called lunar objects. They circle the moon just like Earth’s NEOs but are not big enough to cause significant damage to satellites or astronauts on board a spacecraft. NEOs that do not cross Earth’s orbit do not pose any danger to humans because they travel so far away from Earth’s orbit that it would take a long time for them to come close enough to Earth to cause any damage.
Asteroids can be broken into pieces, which are called meteoroids. When meteoroids enter the Earth’s atmosphere, they burn up completely because they do not have enough mass to survive the heat of re-entry.
Meteoroids are small particles that travel through space in orbit around the Sun. Some of them may become asteroids and others may become comets or interplanetary dust. Some meteoroids are also called asteroids because they orbit around the Sun like planets and some of them also orbit around other stars like moons or planets.
Asteroid orbits are called stable because they can last for millions of years without being disturbed by other objects. Asteroid orbits tend to be inclined at around 0 degrees or very close to it. Some meteoroids, however, do not orbit in stable orbits and instead fall into a chaotic area between the planets or stars that causes them to change their orbits frequently over time.
