Episode details
World Service,19 Feb 1996,9 mins
Discovery of Pluto
Available for over a year
Clyde Tombaugh's discovery of Pluto in 1905 sparked discussions that are continuing today. "Pluto is one of the awkward objects. It's not a proper planet because it's only got a quarter of the mass of the Moon and is quite likely a collection of condensed comets."
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