Poor Pluto

1930  a new planet was discovered by Clyde W. Tombaugh.  It was named Pluto.  The ancients had known of the Sun, the Moon, Mars, Venus, Jupiter, Saturn and little Mercury. 

Neptune and Uranus were discovered in the nineteenth century, and the prediction of a ninth planet which was effecting the orbits of Neptune and Uranus was mooted.

The discovery made headlines across the globe.   The Lowell Observatory which found it had the right to name the new object and received over 1000 suggestions from all over the world, ranging from Atlas to Zymal. 

An eleven year old schoolgirl in Oxford England named Venetia Burney suggested the name Pluto.  She received five pounds as a reward.

Pluto became the ninth planet, a position it held without question until the 1970s when the discovery of Chiron in the outer Solar System and the recognition of Pluto’s relatively low mass led to questions of its categorisation.  Other objects, similiar to Pluto were subsequently located. In 2005 came Eris, which is nearly 30% larger than Pluto.

The blow fell on August 24, 2006. The International Astronomical Union redefined what it meant to be a planet, and Pluto did not qualify.

As a sop it was placed in the new category “dwarf planets”  with Eris and Ceres. A few scientists continue to hold that Pluto should be classified as a planet, but the majority has agreed with the deplanetification.

Alas, Pluto is no longer the ninth planet.