For centuries, planets beyond our solar system—called exoplanets—existed only in theory and science fiction. It seemed nearly impossible to detect planets light-years away, since the ...

It's past midnight in the dim telescope control room, but Dominique Naef's day has suddenly brightened. He twitches his computer cursor over a wavy line. "I like it," the Swiss astronomer says ...

Mountains. Rainforests. The ocean. These critical Earth systems provide some of the most basic needs for life on Earth: water, oxygen, a stable climate. But these systems are increasingly at risk ...

This story appears in the November 2015 issue of National Geographic magazine. Climates change. That’s a fact of nature. But Earth’s climate today is changing so dramatically that it’s ...