A super-Earth planet that dips in and out of its star's habitable zone has been discovered just 19.7 light-years away.

Thirty years after the discovery of the first exoplanet, astronomers have detected more than 7,000 of them in our galaxy. But there are still billions more to be discovered. At the same time, ...

Earth,” dubbed HD 20794 d, boasts a mass six times that of our planet and resides within the star’s “habitable zone.” The ...

Some interpretations of the phrase include the planets lining up on the same side of the sun all right next to each other. The planets can never fully line up exactly like you see in pictures ...