Marek Kukula
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Why is Pluto not a planet?

Pluto lost its status as a planet in 2006 but its reclassification as a "dwarf" world actually puts it into an exciting new category.

Dr Marek Kukula, the Public Astronomer at the Royal Observatory Greenwich, charts the history of the diminutive object that orbits some five billion kilometres from the Sun.

The BBC will be screening a special "Sky At Night" programme called Pluto Revealed on Monday 20 July, which will recap all the big moments from Tuesday's flyby by Nasa's New Horizons probe.

  • 11 Jul 2015
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