The timing of the first human arrival in the Americas remains one of the most debated questions in archaeology. Evidence from butchered mammoth bones, stone tools, and ancient footprints suggests ...

Robert Zubrin, likely the planet’s leading strategist for landing humans on Mars, and then remaking it in the Earth’s image, predicts SpaceX’s colossal Starship will be the first spacecraft ever to ...

Sloths weren't always slow-moving, furry tree-dwellers. Their prehistoric ancestors were huge — up to 4 tons (3.6 metric tons) — and when startled, they brandished immense claws.Video above: ...