This jet streaming out of a supermassive black hole is traveling at nearly the speed of light. Superman may fly faster than a speeding bullet, but he'd easily lose in a race against a beam of light, ...

NORFOLK, Va. — A light year is exactly what it sounds like: the distance light travels in one year. If you need to get somewhere quick, you'd want to jump on this train because light travels through ...

A planet's year length depends on its distance from the Sun. Planets closer to the Sun have shorter years. A planet's rotation speed is unrelated to its year length. Planets' orbital speeds vary ...