Large size of 2003 UB313 fuels debate over what is and isn't a planet.
The recently discovered 'tenth planet' of our Solar System is substantially larger than Pluto, astronomers have found.
The recently discovered 'tenth planet' of our Solar System is substantially larger than Pluto, astronomers have found.
For many, the discovery that object 2003 UB313 is about 3,000 kilometres across will remove any doubt that it deserves to be called a planet.