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LET'S EXPLORE Space

A trip across the Solar System: Pluto

Pluto in an image taken by New HorizonsPluto in an image taken by New HorizonsPluto was once known as the ninth planet of the Solar System—the smallest and most distant planet. Then, in 2006, astronomers agreed it should be called a “dwarf planet”. This was because many objects similar to, or even bigger than, Pluto had been recently discovered in the outer Solar System. Thanks to images sent back by the New Horizons space probe in 2015, astronomers have found out a lot about Pluto.


An animation of Pluto's orbit, viewed from aboveAn animation of Pluto's orbit, viewed from above

Orbit

Pluto has an highly elliptical orbit. This means it is has a stretched-out oval shape. For 20 of the 248 years it takes to orbit the Sun, it lies inside the orbit of Neptune. Pluto's orbit is also tilted at angle to those of the other planets, which all lie roughly on the same plane.


The name Pluto was proposed by Venetia Burney, an 11-year-old schoolgirl from Oxford, England. She received £5 as a reward.

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