The rusty world is full of mysteries—and some of the solar system's most extreme geology. Learn more about Earth's smaller, colder neighbor.

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

The fifth planet from the sun, Jupiter is what watercolor dreams are made of. Vibrant bands of clouds ripple around its thick ...

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

It is a question that feels like it should have a straightforward answer: how many planets are there in our solar system? Since Pluto was relegated back down to dwarf planet status, almost everyone ...

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 ...

Most planet-forming disks have warps that can lead to planets on inclined orbits, which could explain where the tilt of Earth's orbit came from. When you purchase through links on our site, we may ...

Nearly all of the planets in the solar system are about to march through the night sky in a single-file line. This planetary alignment, sometimes called a planet parade, will include all of the solar ...