On the 95th anniversary of its discovery, Pluto remains one of the most beloved and enigmatic worlds in our solar system, ...

So things stood for 65 years. Although Pluto's orbit was more elongated than the other planets' (and even crossed the orbit of Neptune—not the kind of thing you would expect a decent planet to ...

Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

And then he’d go back later and use the blink comparator to compare the photos ... that led to the discovery of Planet X. Pluto never really fit in with the other planets in the solar system.

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's ...

Pluto failed the third criterion. Unlike the eight recognized planets, Pluto shares its orbit with many other objects in the Kuiper Belt, meaning it has not "cleared its neighbourhood." ...

The other four moons ... in the solar system compared with its parent body. In fact, Charon and Pluto are so similar in size that they are considered a double dwarf planet system, not a planet ...

On the other hand, outer planets move very slowly, and we see their influence unfold over time.” She notes that to understand where Pluto is taking us, it’s helpful to look back at where we ...

Take advantage of a special 6-7 planet alignment from Earth's perspective. Planets 'line up' in the skies over California in ...

The other four moons—Nix, Hydra, Kerberos and Styx—are much smaller than Charon. One idea is that Pluto got its moon system when a massive object smashed into the dwarf planet. The resulting ...