This is Why Some Asteroids Act Like Comets

This is Why Some Asteroids Act Like Comets

~!!!~It seems so simple a definition: comets close to the sun have long streams of material behind them, whereas asteroids are more quiet// But it turns out that*s not always the case// Since 1996, we*ve known that some asteroids possess long dust tails similar to what you*d expect on a comet// The object 133P/Elst~Pizarro is thus a **prototype** of **active asteroids,** says Jessica Agarwal, a scientist at the Max Planck Institute for Solar System Research//

~!!!~Comets spent of the time since their formation in the cold outer solar system and started to enter the inner solar system only recently, meaning that much of their primordial ice was preserved// The typical asteroid, however, stays in a belt between Mars and Jupiter with nearly constant heating from the sun for billions of years// So one question researchers are trying to answer is how asteroids can be active when most of their ice is likely gone//