Neptune is 2.8 billion miles away from the ... The number of sand grains and stars equal each other. If these cool space facts have piqued your interest, check out these 13 virtual space exhibits ...

Only one mission has flown by Neptune — Voyager 2 in 1989. Today, there are still many mysteries about the cool, blue planet, such as why its winds are so speedy and its magnetic field is offset.

So I figured I’d take this opportunity to tell you a few things about this comet, a handful of facts to nourish the ... year orbit that takes it out past Neptune. But some are more extreme.