The new clause that boots Pluto (and Ceres) out is that the "dwarf planet" meets all of the qualifications for regular planet but "has not cleared the neighbourhood about its orbit". As indefatigable42 has pointed out, a better way of saying this is that the object isn't unique in the neighbourhood. Ceres isn't, because there are several more quite large asteroids around, and umpteen smaller ones. And Pluto isn't because we know know of several more large objects in the outer solar system, one which is larger than it is. All the eight "classical" planets clearly are.
Also, as has been noted elsewhere Gustav Holst's The Planets has the correct number of movements again!
At the monthly Canadian Space Society meeting Tuesday, we had filmmaker Michael Lennick as our speaker, probably best known for his wonderful Discovery Channel series Rocket Science. His talk morphed away from the stated topic (how acceptance of risk has changed at NASA from the early days of spaceflight) and became more about the forgotten pioneers of the Space Age, like Joe Kittinger, who bailed out from a balloon at 100,000 feet, and how their efforts helped shaped NASA programmes. He has a new show coming up on PBS in the fall on Edward Teller, one of the father's of the H-Bomb (Dr. Teller's Very Large Bomb).
The post-talk talk went all over the place, but he said two things I found particularly interesting. The first was about how he had once considered doing a show about the idiots who don't think we went to the Moon (to be called The Moon Hoax Hoax) and in talking to college students who should have known better, he came away with three reasons they had doubts.
- It was technically possible to have faked it.
- It was "done" by the government, and the government lies to us.
- If we could go to Moon, why can't we now? How could we have forgotten how to do it?