An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

The potential discovery of a large planet beyond Neptune’s orbit could change everything we know about the Solar System.

21. A planet parade is when several of our solar system's planets are visible in the night sky at the same time. There will be six planets visible this time around, including Venus, Mars ...

Narrator: Further from the Sun, in the outer reaches of the solar system, we find the gas planets. Much larger than the rocky planets, these cosmic giants are accompanied by numerous moons.

Everyone knows about the Solar System, and the planets that make it up. They’re in space, orbiting the Sun, in an order we all at least used to be able to recite. But it was not always so.

With a radius of 2,106 miles, Mars is the seventh largest planet in our solar system and about half the ... which is called a sol (short for “solar day”). Mars’s axis of rotation is tilted ...

There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond the eighth planet Neptune. The tantalizing prospect of a ninth ...

When will we be able to see the planets at their best during this upcoming year of 2025? This guide will tell you. It will also provide information as to when a particular solar system planet ...

In fact, every planet—and every moon—in the solar system will be in the sky during the eclipse. However, that doesn’t mean you’ll see them all. Contrary to what you might have read ...

With a radius of 3,959 miles, Earth is the fifth largest planet in our solar system, and it's the only one known for sure to have liquid water on its surface. Earth is also unique in terms of ...

One possibility is that a rogue planet, about 1–2 times Earth’s mass, influenced their paths early in the solar system's history. Another enigmatic group comprises high-inclination TNOs ...

The findings reveal the distribution of ices in the early solar system and how TNOs evolve when they travel inward into the region of the giant planets between Jupiter and Saturn, becoming centaurs.