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Active asteroids are celestial bodies that, unlike "normal" asteroids, show cometary activity. This means that, in addition to their orbital motion around the Sun, these asteroids also have the ability to release gases and dust into space, creating a kind of coma or tail around them.
This cometary activity is due to the evaporation of ice and other volatile materials on their surface.
The main difference between active asteroids and "normal" asteroids lies in this cometary activity.
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While "normal" asteroids are rocky, metallic bodies that do not show significant volatile activity, active asteroids exhibit cometary characteristics such as outgassing and tail formation.
This activity can be the result of different processes, such as the sublimation of water ice or the outgassing of other volatile compounds on their surface.
Active asteroids are often classified as cometary asteroids or "cometoids". Although they are called asteroids, their behaviour more closely resembles that of comets.
These celestial bodies can show changes in brightness and appearance as they approach the Sun and volatile materials evaporate. In addition, the presence of a distinctive coma and tail distinguishes them from "normal" asteroids.
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It is important to note that the distinction between active asteroids and "normal" asteroids is not always clear and definitive. Some asteroids may show cometary activity only temporarily, while others may show mixed characteristics, sharing features of both asteroids and comets.
This has led to a greater understanding of the close relationship between asteroids and comets in the solar system.