Are we alone? It’s a question that has obsessed us for centuries, and now we have the technology to do more than wonder. Scientists on the hunt for distant planets and extraterrestrial intelligence explore faraway galaxies and barely...

A few decades ago, we knew of no other planets beyond those in our solar system. Today, astronomers have confirmed over 700 planets circling other suns and believe billions more lay undiscovered. These new worlds have smashed...