In the crowded early Solar System, young planets frequently collided and reshaped each other. But Mercury stood out. It formed unusually close to the Sun. Mercury’s days are longer than its years. It ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system?

With a lot of talk about space recently, have you ever wondered which are the hottest planets in the solar system? You'd think the closer you are to the sun, the hotter they must be. Now that's mostly ...

Astronomers have found new evidence, revealing the existence of an unseen and mysterious planet that could be hidden in the ...

LYNCHBURG, Va. (WSET) — If you're trying to get a beautiful look at the planets in our solar system, you're in luck. Between February 25 and February 28, all seven planets in our solar system will be ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...

From lava worlds to gas giants, NASA says the variety of these worlds is staggering—and that signs of a further 8,000 distant ...