The solar system lost its ninth planet back when Pluto was demoted to a dwarf planet, but research might indicate that there ...

Astronomers have uncovered a massive new trans-Neptunian object, 2017 OF201, lurking at the edge of our solar system. With an ...

Most planet-forming disks have warps that can lead to planets on inclined orbits, which could explain where the tilt of Earth ...

WHETHER or not you believe in life beyond Earth, there are actually a minimum of 100 billion planets in our universe, according to a Nasa study. But how many planets make up our solar system?

Think of our solar system like a big family. The Sun is the parent, and the eight planets are like siblings. Each planet is unique, just like how every person in a family is different.

New discoveries of objects in the Kuiper Belt have also presented challenges for the Planet Nine theory. The latest is known ...

A quick guide to planets, including the eight in our solar system, how they form, and how many could be in the universe.

This star, known as HD 110067, may have even more planets. The six found so far are roughly two to three times the size of Earth, but with densities closer to the gas giants in our own solar system.

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago.

Earth is the planet we have the best opportunity to understand in detail—helping us see how other rocky planets behave, even ...

From the scorching surface of Mercury to the icy edges of Neptune, our planetary neighborhood is full of wonders. The order of the planets isn’t just trivia—it tells a story about temperature, ...