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

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

But in reality, none of the eight planets follow perfectly circular orbits, and they don't all lie on the same plane either. Earth's orbit, for example, is oval-shaped, and there is a seven ...

Space is all around us. We live on planet Earth but there are loads more planets up in space. There are also stars and moons. The closest star to Earth is the Sun. In our solar system there are 8 ...