Okay – here’s the deal. I’m getting a little tired of this Pluto’s-Not-A-Planet crap. Why, I ask, would Pluto be considered to be anything other than a planet? ‘Why?’ The answer goes, ‘Because it doesn’t fit the definition of “planet”‘.
Huh? When did this happen?
2006. That was when the International Astronomical Union (IAU) decided (for whatever reasons) to write a new definition of ‘planet’. Their definition is as follows:
1) Have an orbit around a sun.
2) Have enough mass to assume a (mostly) round shape.
3) Have cleared the neighborhood in its orbit.
The third is the one Pluto falls short on, and for this reason they’re now referring to it as a ‘dwarf’ planet. There are some in the profession fighting this (mostly because expecting Pluto to clear out the neighborhood is unreasonable, due to the enormity of its orbit), but so far they have been unsuccessful. My take on this is that the IAU is going at this ass-backwards.
Years ago, the archaeological world had a list of criteria they used to define a ‘civilization’ (much like our planet-defining list above). If I remember correctly (and I usually do), there were 5 items on the list, the pertinent one being possession of the wheel. It was thought that a group of humans couldn’t reach the lofty heights of true civilization without first developing the wheel. Then one guy, who had spent his life studying the Inca, raised his hand and said: “But – the Inca never developed the wheel”. He was told that the Inca, having failed to measure up to the definition, couldn’t have been a ‘civilization’. “But,” he argued, “They Built Machu Picchu. They had a trade network that spanned a continent. They had suspension bridges, for Christ’s sake!”
“Hmmm,” said his colleagues, “Maybe we should re-think our definition.”
This, my friends, is how science is supposed to be done. A good scientist does not look up on a overcast day and say: “It’s not blue, therefore it cannot be the sky”.
Pluto has enough of a gravitational influence on our solar system that it’s presence was known decades before anyone actually ‘saw’ it. It has three moons (that we know of), putting it ahead of Mercury, Venus, Earth and Mars. Most importantly, in the decades during which Pluto’s existence was known but it had not yet been ‘seen’, it was known as “Planet X”. This alone gives it more celestial street cred than all the other so-called planets combined.
It’s a friggin’ planet. Just fix the definition, already.
Besides, we don’t really want to piss off the god of the underworld, do we?