Asteroids, meteors, bolids, meteorites, comets… What are their differences

Although space may seem a distressing and empty place, the truth is that it is full of millions of roaming travelers that, from time to time, can be seen from Earth. There are several types of them, and you’ve probably wondered more than once how to distinguish them. Here are some clues:

Asteroids: rocky masses smaller than a planet and larger than a meteoroid and orbiting the Sun usually from the asteroid belt between Mars and Jupiter or the Kuiper belt. E.g.: Oumuamua, the presumed interstellar visitor.

what are the differences between asteroids, meteors, meteoroids, meteorites-astronomy-oumuamua
Oumuamua, the interstellar traveler that visited us in 2018, is an asteroid with several peculiarities that has raised the idea of its artificial origin among some astronomers. ABC

Meteoroids: fragments of asteroids or comets composed of rock, dust, and ice.

Meteors: is the luminous phenomenon attributed to meteoroids when they enter the Earth’s atmosphere and, due to friction, heat up to become incandescent balls that often end up volatilizing completely. They are better known as “shooting stars” and are the cause of meteor showers (Perseids, Leonids, Orionids, etc.).

what are the differences between asteroids, meteors, meteoroids, meteorites-astronomy-orionids-perseids-leonids
The misnamed “shooting stars” are actually incandescent fragments of asteroids or comets due to the friction with the atmosphere. Geofriks blog

Bolides: these are the brightest meteors, such as that of Chelyabinsk (2013). They usually end their journey with an explosion before reaching the ground, giving rise to smaller fragments (meteorites).

what are the differences between asteroids, meteors, meteoroids, meteorites-astronomy-bolide of chelyabinsk
The Chelyabinsk bolide flew over Chelyabinsk until it exploded, spitting out a multitude of debris or meteorites, some of which have been recovered. DW

Meteorites: fragments of meteoroids surviving their passage through the atmosphere that reach the Earth’s surface, so they must be large enough.

what are the differences between asteroids, meteors, meteoroids, meteorites-astronomy-the dagger of tutankhamun is made of meteorite
The composition of a ritual dagger found in the tomb of Pharaoh Tutankhamun revealed its meteorite origin, like many other Bronze Age objects. La Vanguardia

Comets: objects orbiting the Sun formed by ice, dust, and rock and often confused with meteors. As they approach the Sun, an atmosphere of dust and gas by the evaporation of the ice is generated around the nucleus called coma, visible thanks to the refraction of sunlight. When the solar wind hits this envelope, the tail is generated. They come from the Kuiper Belt and the Oort Cloud, at the edge of the Solar System.

what are the differences between asteroids, meteors, meteoroids, meteorites-astronomy-Halley's comet
The best known example of a comet is Halley’s comet, which completes an orbital cycle around the Sun every 75 years on average. Wikipedia


  • Barquero, J.I. (2010). Manual de astronomía. Managua: Asociación Nicaragüense de Astrónomos Aficionados.

  • Space Place (2021). ¿Asteroide o meteoro: en qué se diferencian? NASA. June 31, available in:  

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