Entry 22: In Which We Geek Out A Little Bit.

Here is a totally awesome link:

http://kokogiak.com/solarsystembodieslargerthan200miles.html

This lines up all the bodies in the solar system according to size. It's a superb visual aid, especially for people like me who have a hard time with scale. I can never get a good handle on relative size from looking at the numbers; this picture makes it easy. And it's pretty, too!

The effect as you scroll sideways across the page is quite impressive, and in some cases surprising. For instance, I had no idea Titan and Ganymede were that big.

It also nicely illustrates the whole Pluto/planet/dwarf planet/TNO controversy. Again, from reading articles and looking at the numbers, I didn't quite understand the argument, but the picture shows with perfect clarity why it's sketchy to class Pluto along with the other planets. It also explains why, if want you call Pluto a planet, you absolutely have to call Eris a planet as well. (Though personally I think Ceres is stretching it a bit.)

So we no longer have nine planets in the solar system. We either have eight if you drop Pluto or ten if you add Eris (or eleven, I guess, if you take Ceres as well). Which means the old mnemonics for remembering the order no longer apply. "My Very Educated Mother Just Served Us Nine Pickles" is sadly out.

Any ideas for new mnemonics?

If you choose to drop Pluto, the order would be: M V E M J S U N.

If you prefer to keep Pluto, which means you have to add Eris and probably Ceres, the order would be: M V E M C J S U N P E.

Come on, I'll bet you can think of some good ones......