Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

Siraj’s Planet Y search started about a year ago when he was trying to find out whether the shape of the Kuiper Belt is flat. “The planets of the solar system have slight tilts up and down, but ...

Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our solar system.

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be fair—but one of the largest yet discovered and with an orbit around the Sun that ...

When you look at the solar system, you might notice that the planets' orbits are tilted, and oddities in the protoplanetary ...

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...