The Solar System

18 articles

The Sun, eight planets, moons, asteroids and comets moving together in a system 4.6 billion years old.

Liquid water, an oxygen-rich atmosphere, a protective magnetosphere and plate tectonics - four rare conditions on one world.

It once had rivers, lakes and perhaps an ocean. Understanding how Mars lost its water is understanding how a world stops being habitable.

More massive than every other planet combined times 2.5, with a Great Red Spot storm at least 350 years old.

Rings spanning hundreds of thousands of kilometres yet ten metres thick in places, plus Enceladus venting salty water into space.

A 98° axial tilt gives each pole 42 years of continuous daylight followed by 42 years of night.

Predicted from orbital perturbations before anyone saw it, and home to the fastest winds in the Solar System.