Sloths, the world's slowest mammal, have been around for 64 million years. Sharyn Alfonsi traveled to Costa Rica to learn ...

In Stranger Things, the Upside Down isn’t just a terrifying alternate dimension filled with monsters—it’s also a powerful ...

A time-lapse view of Antarctica & the moon can be seen in footage captured by the Meteosat-11 satellite. Credit: Simon Proud ...