Scientists have detected a hidden alien planet by examining the orbits of the known worlds in the star system, known as Kepler-139. The newfound exoplanet, called Kepler-139f, is a gigantic world ...

"It was just a matter of time before we found them." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Thirty years ago, on Oct. 6, 1995, the very ...