The last time a crew of Americans rode a rocket toward the Moon, the country was reeling from assassinations, riots, and a ...

Anyone who steps onto Mars will be crossing a one-way threshold in more ways than one. The physics of getting there and back, the biology of living in low gravity, and the psychology of leaving Earth ...

A mystery that started with the discovery of a pinkie finger bone in Denisova Cave in the Altai Mountains of southern Siberia may finally have been cracked.