It must have cleared all other celestial bodies, except its own moons, from its orbit.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Our solar system ...

A Southwest Research Institute-led team combined compositional data of primitive bodies like Kuiper Belt objects, asteroids ...

Though technically not a planet, it has as rich geology as any of its planetary siblings in the solar system A color-enhanced photo of Pluto that was captured by the New Horizons spacecraft in ...

As the final planet in our solar system, Pluto is rightly linked to endings ... the planet “tests” the mettle of its children in order to cast out what holds them back. Use a birth chart ...

than any of the planets in the outer solar system. Nevertheless, because it orbited the Sun like a planet, it was classified as a planet and named Pluto, after the god of outer darkness in Roman ...

The researchers revealed that Uranus’s protective magnetic field was distorted, and seemed wonky and weak, being squashed and ...

As technology continues to progress, though, could we uncover a new one? Astrophysicists don't know if there are ...