Interstellar space is unforgivingly vast, but the emptiness has some advantages. The lack of atmosphere means there is no aerodynamic drag.

To assess the plausibility of alien visitors, it’s necessary to understand the obstacles that an extraterrestrial vessel would need to overcome to reach Earth ...

Barack Obama's insisting the USA doesn't have little green men or alien spaceships locked up in an underground bunker somewhere ... but, if they ever visit Earth, he's volunteering to lead the ...

A mysterious object spotted hurtling toward Earth has sparked a wave of global panic and wild alien invasion theories online.