Once known as the ninth rock from the Sun, Pluto had its planetary status downgraded nearly a decade ago to the less impressive “dwarf planet” or “plutoid”. Now the head of the first mission to Pluto, which begins scientific observations today, is mounting a campaign to have it reinstated to its rightful place.
Alan Stern, the principal investigator of Nasa’s New Horizons mission, said: “I think the public will discover it’s been a planet all along. When they see it close up, they won’t know what else to call it.”
Pluto’s demotion, by the International Astronomical Union shortly after New Horizons was launched in 2006, was a decision that Dr Stern considers “a gross mistake that is an embarrassment to astronomy”.
The £460 million mission