Related topics: earth · nasa · solar system · orbit · meteorite

NASA volunteers find 15 rare 'active asteroids'

Some extraordinary asteroids have "activity"—comet-like tails or envelopes of gas and dust. NASA's Active Asteroids project announced the discovery of activity on 15 asteroids, challenging conventional wisdom about the ...

What's the earliest the moon could have formed?

Astronomers are pretty sure they know where the moon came from. In the early solar system, a Mars-sized object dubbed Theia smashed into Earth. This cataclysmic collision knocked a huge mass of material into orbit, which ...


Asteroids, sometimes called minor planets or planetoids, are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are smaller than planets but larger than meteoroids. The term "asteroid" has historically been applied primarily to bodies in the inner Solar System since the outer Solar System was poorly known when it came into common usage. The distinction between asteroids and comets is made on visual appearance: Comets show a perceptible coma while asteroids do not.

This text uses material from Wikipedia, licensed under CC BY-SA