Hello, titch!

So Pluto is very much in the news at the moment following the pictures and data provided by the NASA space probe New Horizons.  But is it a planet?  It was considered so when it was first discovered in 1930, but in 2006 the International Astronomical Union reclassified it as a "dwarf planet" - a category which had not existed before then,  But why did they do it?  It seemed a bit mean-spirited at the time I seem to remember.  However it is now clear that the decision was taken on purely practical grounds.  Advances in space detection meant that new bodies were regularly being discovered in the outer reaches of the solar system, many of which were as big, or bigger than Pluto. And of course if Pluto was to be considered as a planet, these would also have to be similarly classified.  And it's bad enough having to remember eight planets - imagine having to cope with three or four times that number!  So by designating these as dwarf planets, it keeps the number of "proper" planets within reasonable bounds.