The demotion of Pluto was bad science, and everyone knows it. They started with the determination that Pluto wasn't to be a planet, then worked backwards from that to get a definition that by rights ought to exclude every single other planet except Mercury if it weren't for all the special handwaving to explain why it…

satellite and moon are pretty much used interchangeably by astronomers, at least in casual conversations with the public. Same with using "sun" and "star" interchangeably. Some will only use moon only when talking about Earth's moon and sometimes they will capitalize to treat it like a proper noun to distinguish it.…

The proper term I believe is "barycenter".

The center of rotation is fully outside Pluto's diameter, and it is a binary system.

Wouldn't this "wobble" make Pluto and Charon a binary system? Or must the center of rotation lie completely outside the diameter of the composing bodies?

Pluto is and should be a planet. Pluto has 5 moons, which is kindof odd for a not-a-planet planet.

http://www.scientificamerican.com/podcast/episod…

You know, I love me some Neil DeGrasse Tyson, but the man is wrong about Pluto not being a planet. 5% of professional astronomers voting to demote Pluto is and was ridiculous. And at some point they will hopefully revisit the issue and revote.

Now imagine what we could do with it if we funneled all of it into the NIH, biosciences, and public health research. We might have become transcendent beings or some shit.

Keep in mind there is room for Pluto. When he comes again...

And for old time's sake, we can even include our pal Pluto (2,302 km)!

It is different, but that should have no importance on it being a planet. The terrestrial and gas giant planets are every bit as different from one another as they are pluto. And, as other planets are discovered in other solar systems it is apparent that eccentric orbits are common for even some gas giants. Let's say…

One of these things is not like the others. And that one is Uranus. It is the only planet in the solar system that orbits on it's side. Therefore, it should be demoted and no longer a planet.

You can pry Pluto's planethood from my cold, dead hands.

There's no room for orbitism in the 21st century.

Exoplanet studies already confirm multiple systems with multiple planets in skewed inclinations.

However Ceres does. This is why there needs to be multiple conditions. Even the official IAU definition leaves Earth's planetary status up to interpretation (supposed to have cleared orbit, but there's another large planetary object sharing the same orbit, which influences the Earth).

A pat on the back from me to your nephew's teacher!