This cache is part of a 1:133,700,000 scale model of the solar system. The dome on the Monroe County Courthouse in downtown Bloomington, Indiana serves as the model of the Sun, and all the planets, dwarf planets, moons, and asteroids are all constructed to the proper size and placed at the proper distance based on that scale.
As always, please put everything back as close to how you found it as possible (except for Nereid, which can go anywhere between 3 and 237 feet from Neptune (see below)). Make sure the camo is back in place so that no civilian passers-by will catch any curious glimpses of blue in case they wander off the trail for a call of nature. You shouldn't need to move any of the moons except for Triton (and Nereid, if you feel like challenging the next cache-seeker) There's a a lot of good loot in there for trading. There's also a remote-control helicopter as a first-to-find prize.
You might be wondering why such a newly published cache looks like its been out in the woods for half a year. The cache has been around since August 2011, but due to a minor technicality, it couldn't be published until I got a chance to come back and fix something, and I took way too long before getting around to that.
You might be thinking that this is a bit far away for a solar system model centered in Bloomington, but keep in mind that Neptune is the furthest true planet from the sun. Yes, this means that I'm one of those heartless bastards that distinguishes Pluto as "only" a dwarf planet. (Of course that doesn't exempt Pluto from the series.) Neptune ranges from about 4.45 to 4.55 billion miles from the sun, which corresponds to a range of 20.7 to 21.2 miles at this scale. I placed this model almost all the way out to its aphelion (the furthest point from the sun), almost 20.7 miles away from the courthouse. To give you a sense of perspective, the entire inner solar system (including Mercury, Venus, Earth, Mars, and all the asteroids that are in the asteroid belt) all fit within the city limits of Bloomington. There is stuff even further out than Pluto.
Neptune is about 49,500 kilometers wide and 48,700 kilometers tall, so this model is roughly 14 inches in diameter. When you find the model, you might be surprised by its fairly boring appearance. Sadly, this is pretty close to what Neptune actually would look like if you could look down on it from a spaceship. Those pictures you're used to with all the pretty white cloud streaks of clouds and menacingly dark storm spots have all had their colors tweaked to bring out those details that you can't see with the naked eye. Of course Neptune is not perfectly uniform in its appearance, and neither is this model. If you look closely, you should be able to make out some variability in the colors, and you might even be able to spot a dark storm cloud in the northern hemisphere. Unlike Jupiter's great red spot, which is a permanent (from the point of view of human lifespans) feature of the planet, dark spots on Neptune like this come and go every few years. As of the time when the cache was hidden (August, 2011), there was a large dark spot like this in the northern hemisphere of Neptune, which is why I included one on the model.
So far, we've discovered thirteen moons orbiting Neptune. Most of them are so small that they would be less than a millimeter across at this scale, so I haven't included them in the model. The four closest moons (Despina, Galatea, Larissa, and Proteus) are all fairly ordinary rocky satellites with straightforward orbits, no more than a few hundred kilometers across. Their orbits keep them all at about 50,000 - 170,000 kilometers from Neptune, so the moons' models are no more than a couple feet from the planet's model. The models are pebbles a few millimeters across that were carefully chosen to have roughly the right dimensions and color. Well, two of them are pebbles. The other ones washed away in the rain. They're so small that they'd be almost impossible to find on their own, so they've been attached to reflective firetacks, on which are written the digits necessary to open the combination padlock. Unfortunately, the weather washed away two of the digits, and since it also rusted the combination lock permanently closed, there's not much point in replacing them. I've rigged the cache so you only need to open one of the padlocks now.
I've also included the more erratic moon Nereid, which is similar in size, shape, color, and composition to the other small moons, but it has a very eccentric (elongated) orbit, taking it from 130 thousand to 9.655 million kilometers from Neptune. So Nereid's model is somewhere between 3 and 237 feet from Neptune's. (The original model pebble washed away, so it's also a black dot now.) There's no number on Nereid's firetack, but if you find it and take a picture of it, you'll win a free No Prize. To make it easier to distinguish from the other moons, Nereid is on a red tack (the others are all white). After you take the picture, feel free to move Nereid to a new location, as long as it's between 3 and 237 feet from the model of Neptune (and don't put it on the ground, that's just mean).
Neptune's biggest moon by far is Triton. Triton is about 2,710 kilometers across and it orbits Neptune at a distance of about 350,000 kilometers, so its model is about 2 centimeters in diameter, and it's been placed about 8'9" from the model of Neptune. It is attached to the key that unlocks the larger padlock. Unfortunately, the original model of Triton and its key has disappeared (probably due to the weather). There's a pretty good chance that it hasn't gone far, but I couldn't find it the last time I looked. I had a replacement key handy, so I didn't search too hard for it. You can still open the cache with the replacement key (remember to put it back!), but if you find the original lying around, I will be eternally grateful! It's a colorful place with patches of pink, blue, and white ice all over it.
Special thanks to DJHobby and MonsterCatAmbush who helped me find a good spot to hide this monster.