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.
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.).
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).
Meteorites: fragments of meteoroids surviving their passage through the atmosphere that reach the Earth’s surface, so they must be large enough.
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.
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: https://spaceplace.nasa.gov/asteroid-or-meteor/sp/