As Sir David Attenborough celebrates his 100th birthday, new PBS documentary delves into his life and career.

Ah, Earth. We may not think about our planet on a day-to-day basis, but the world we live in is a pretty interesting place. The third rock from the Sun—and to this day, the only one with known ...

Add Yahoo as a preferred source to see more of our stories on Google. Ah, Earth. We may not think about our planet on a day-to-day basis, but the world we live in is a pretty interesting place. The ...