Human footprints stir the imagination. They invite you to follow, to guess what someone was doing and where they were going.

Researchers say the footprints were left in the mud by two different species, perhaps within a matter of hours or days.

Human footprints stir the imagination. They invite you to follow, to guess what someone was doing and where they were going.

The Sagittarius A* supermassive black hole at the core of the Milky Galaxy may be "warping the spacetime surrounding it into ...