This weekend, six planets are set to share the sky in a rare “planet parade,” giving stargazers a short but magical window to ...

It was almost 100 years ago that Clyde W. Tombaugh discovered Pluto. That was the last planet found until 1992, when humans found another one. But this new planet wasn't in our solar system—it was ...

This artistic photo compilation compares the size of Planet Nine (right) to Earth (left). Dr. Konstantin Batygin, professor of Planetary Science at Caltech, made a joke that turned out to be true. In ...

Mercury, Venus, Neptune, Saturn, Uranus and Jupiter will appear together shortly after sunset on Feb. 28 — but is this the "planet parade" we've been waiting for?

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, Pluto was officially reclassified as a dwarf planet by the International ...

Sky gazers across the U.S. will have a chance to see an extraordinary celestial event on Friday as all of the planets in our solar system will appear in the evening sky. This phenomenon known as a ...

It wasn’t all that many years ago that you could go to a major astronomy meeting and hear the latest news about galaxies and supernovas and quasars and the Big Bang — but nothing at all about planets ...

Sky gazers across the U.S. will have a chance to see an extraordinary celestial event on Friday as all of the planets in our solar system will appear in the evening sky. This phenomenon known as a ...