Read all about the eight different planets in the Solar System - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune - and how they differ. Plus, find out why Pluto was reclassified as a dwarf planet in 2006, and discover fascinating facts about tidal forces.

The dwarf planets: Pluto, Ceres, Haumea, Makemake and Eris
We’ve all heard of the planets, but what is a dwarf planet? And why isn’t Pluto a planet anymore?
15 awe-inspiring astronomy discoveries
Discover 15 incredible astronomy facts that might just change how you see the Universe
The James Webb Space Telescope’s first year of images
Royal Observatory astronomer Julienne Hisole looks back on what we’ve learnt from the pioneering space telescope’s first 12 months of observing
21 amazing astronomy events in 2021
From spectacular meteor showers to bold new space missions, Royal Observatory astronomers pick their night sky highlights.
10 Sep 2020
Possible signs of life in Venus’ clouds
While Mars may be the planet that springs to mind when there are discussions of possible alien life in our Solar System, a publication on the discovery of a rare gas (phosphine) in Venus's atmosphere may mean that there is more than one planet that possesses the potential for life.
7 female scientists you might not have heard of
Einstein, Newton and Galileo are names we have heard numerous times. But who are the women who have changed the world of science, and why don’t we know their names too?
What is the transit of Mercury?
The last transit of Mercury took place on 11 November 2019. Find out more about the science behind this extremely rare astronomical event
What is a planet in opposition?
The best time to see and photograph a planet is when it is at opposition. Find out more and check the key opposition dates for Mars, Jupiter, Saturn, Uranus and Neptune
What would happen if the Moon disappeared?
Do we really need the Moon in the night sky? What is its actual purpose?
How long is a day on Mars?
Find out how we measure time on the Red Planet, and what to expect in a Martian calendar year