If alien civilizations rise and fall, they may leave behind artifacts long after they are gone. From abandoned megastructures ...

If thousands of years from now aliens landed in the crumbling ruins of Washington, D.C., what would they make of it? Ellen Harvey has a wild imagination. These days, the artist has been musing about ...

Enrico Fermi’s decades-old question—“Where is everybody?”—remains one of science’s most haunting mysteries. If the universe is teeming with stars and planets, and life has evolved on Earth, why hasn’t ...