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

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.

Planet Nine – which scientists think might be 10 times Earth’s mass – could be lurking out past Pluto’s orbit. But Planet Nine might not be all we’ve missed in our solar system.

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home.

From the slate gray of Mercury to the ruddy brown of Pluto, the worlds in our solar system are a veritable rainbow of colors. But what makes them all look so different?

Mysterious Planet 10 could be hiding out beyond Pluto Move over, Planet 9. There's a new possible planet lurking out in the solar system and it could be messing with a whole lot of distant space ...

From Mercury to Pluto (and maybe even Planet Nine), here are some of 2023's most intriguing discoveries about the planets, moons and other bodies in our solar system.

When it comes to real planets—bodies with enough mass to achieve a nearly round shape, clear nearby debris, and orbit the sun—we know of only eight in our solar system.

The Goblin, officially named 2015 TG387, joins other small objects far out in our solar system, and it adds to a tantalizing theory about another much more massive “Planet X” hiding beyond ...

Go look at The Planets Today. Notice anything strange? The planets are all on one side of the Solar System, with Earth somewhere in the “middle” of the cluster. While this is normal, natural ...