A science teacher explains: Why Pluto, now a dwarf planet, remains a complex mystery - The Indian Express

The word “planet" has been redefined over the years since it was first coined centuries ago by ancient Greeks.

Until the year 2006, every school science book harped upon there being nine planets and thereafter the count got revised to eight! After 76 years since its discovery in 1930, during the International… [+4001 chars]

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