Ten or fifteen years ago, they actually built a scale model of the Solar System up in up in northern Maine. As you drive north on Rt 1A, there's a particular rest stop with a shadowbox on the wall. Inside is a very small small sphere (size of a large marble). The label says "Pluto", with no further details. Keep driving until you get to Caribou or Limestone (I forget which) and you'll pass all the other planets. Some are inside (where there is a convenient building at the right distance), some are on purpose-built display poles by the roadside. When you get to the end, you can find the Sun painted on a wall -- or, at least, the very small arc of it that fits on a wall that size.<p>The planets are all carefully painted to look as accurate as possible and quite attractive. There's no explanation anywhere, you just have to be "in the know". It's an awesome treasure hunt to find them all.