The official story, according to NASA, is this:
Discovered in 1930, Pluto was long considered our solar system’s ninth planet. But after the discovery of similar intriguing worlds deeper in the distant Kuiper Belt, icy Pluto was reclassified as a dwarf planet. This new class of worlds may offer some of the best evidence about the origins of our solar system.
Wouldn’t it be fun if there was some sort of meta story going on, though? That said, the real story is the New Horizons mission to send a probe to Pluto and beyond to the Kuiper Belt. This mission began in 2006 and the New Horizons spacecraft is due to reach Pluto around 14 July 2015, a little over 52 days as I write this. It will probably send back the best images we have of Pluto.
The fact that this spacecraft has been heading to Pluto for about 9 years is a reminder of just how vast our solar system is. Here is a mission overview:
You can follow mission updates on Twitter @NASANewHorizons:
If you are curious what the differences between a dwarf planet and a planet are, watch this short video too: