Scientists have been searching for evidence of extraterrestrial life for decades. So, where are all the aliens? Here are 12 intriguing theories ...

It’s been a fascinating year in earth science—from mysterious “dark oxygen” to an “unidentified seismic object,” here are ...

It too returned safely to Earth. Here's one story that'd be hard ... On the 1969 Apollo 12 mission, the people who prepared the notebooks decorated them with cartoons and porn copied from "Playboy." ...