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

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

Graphic visualisation of NASA's Solar Dynamics Observatory (SDO) shows a vast 500,000 mile-wide coronal hole in the sun's ...

From January to March, the night sky will host a spectacular parade of planets featuring Venus, Mars, Jupiter, Saturn, Uranus ...