Аннотация:The problem of asteroid activity arose about 20 years ago. It started from discovering a few small objects in the Main asteroid belt (MAB) with clear but temporary cometary features originated possibly from impact events. Shortly after that, the presence of active bodies among asteroids with predominantly silicate composition was explained by supposing these bodies to be comets from the neighboring comet family of Jupiter. However, the result of the 20-year search for new active objects was that about half of ~40 found bodies actually are classic asteroids. Therefore, the solution of this problem may be more complicated and likely associated with the presence of ice on the asteroids themselves