When astronomers announced Kepler-452b, they were not just adding another distant world to a growing catalog. They were ...

Since it first premiered in 1993, the "Power Rangers" series has introduced hugely powerful characters both evil and good. Here's how they rank.

Paul Bennewitz believed he found proof of alien communication near a U.S. air base. At first, the Air Force played along — even funded his research. But when he got too close to something real, they ...