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T. E. Williams

Yeah! That last paragraph is right on. Kids are perfectly capable of understanding how things get changed and renamed, and it would be good for the adult public at large to understand how fundamentally our understanding of planetology has changed since they went to school in decades past.


Is there a provisional list somewhere of the 30-odd spherical-bodies-orbiting-the-Sun?

Oliver Morton

I guess my provisional list was the nine canonical "planets", seven big moons, and the same number again in big TNOs like Sedna and the largest asteroids (Ceres, Pallas, Vesta, I think, maybe more) Maybe Amalthea and Charon, too. It was a pretty loose guesstimate. Anyone who wants to put together a better one should feel welcome (but remember there will be more big TNOs to include, by and by...)

Bruce Moomaw

Actually, Amalthea is about 1.5 times longer than it is wide. And the real problem is the intermediate cases. Vesta is very seriously flattened at the poles; and Neptune's second biggest moon, Proteus, looks like nothing so much as a giant marshmallow. No doubt there are plenty of such intermediate cses among the KBOs, too.



Kevin Shuman

Oh come on now,of course Pluto is a planet.It has one feature which none of the other objects mentioned has.Pluto has a moon and that makes it a planet.

Oliver Morton

Some asteroids -- quite possibly a lot of them -- have moons, too. They don't even have to be particularly large asteroids...


Only the Moon. It is close enough that, detpsie being relatively small, it can cover the disk of the Sun. The Moon casts a shadow and it is when this shadow passes over Earth (and you stand in that shadow patch) that you would see a total eclipse of the Sun.Venus and Mercury are bigger than the Moon, but they are much further away from us. Their apparent diameter is therefore too small to block off the light of the entire Sun's disk. When they pass in front of the Sun, it is called a transit .There will be a transit of Venus in June 2012 (just as there was one in June 2004).No comets or asteroids are big enough to block off the Sun, regardless of how close they pass to Earth. And no, they cannot cause earthquakes. The idea that something could pass between us and the Sun, causing an eclipse AND earthquakes comes from the Planet-X hoax (the original one, for May 13, 2003 the Big 2012 Hoax is simply a recycling of that hoax).The charlatans who played up the hoax used the story to scare people and then make money by selling them books on how to survive.


Ich hatte schon fcberlegt, ob ich nicht dieses Jahr mal thenlieme an der Konferenz, aber die Organisatoren machen es einem nicht gerade einfach die Buchungs- und Bezahlmethoden von SIS sind noch nicht mal im letzten Jahrzehnt des vorigen Jahrhunderts angekommen: keine Emailadresse, keine Kreditkarten, kein PayPal :-(

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