An excerpt from an OUPblog article published on 4th May 2016, written by the Oxford Reference marketing team.
'What is a planet? As defined by Oxford Dictionaries it is ‘a celestial body moving in an elliptical orbit round a star’. In our own Solar System, it was traditionally thought that there were nine such planets: Mercury (the closest to the Sun), Venus (the slowest rotating planet in our Solar System), Earth (our home), Mars (which is slightly pear-shaped), Jupiter (which has over 60 moons), Saturn (encircled by bright equatorial rings), Uranus (which has a peculiar magnetic field), Neptune (a gas giant), and Pluto.'
Discover more: Find out which planet you would be by taking our quiz on the OUPblog.