Comets are loose collections of ice and dust, sometimes with long tails. Asteroids are more rocky or metallic. Now astronomers have found a comet-like double asteroid.
Bright stars like Antares twinkle, while planets like Saturn tend to shine with a steadier light. Scrutinize Antares and Saturn over these next few evenings - or when the moon moves away - to see if one twinkles more than the other.
