The Universe seems empty of alien civilizations, but could they simply be hiding, and if so, how would they do so?

The curious minds at Aperture playfully ask whether Neil Armstrong’s arrival made humans the first aliens on the Moon.

Earth and our entire Milky Way galaxy may sit inside a mysterious giant hole which makes the cosmos expand faster here than in neighboring regions of the universe, astronomers say.

Scientists aren't sure whether Earth will be fully swallowed by the Sun, or merely burned to a crisp. Which sounds better to ...