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, and large moons are all
constructed to the proper size and placed at the proper distance
based on that scale.
I know what you're thinking: Isn't Louisville, Kentucky a little
far for part of a model that's supposed to be in Bloomington,
Indiana? Well, Sedna ranges from about 11 to 144 billion
kilometers from the sun, so in this model, Sedna had to be placed
between 53 and 678 miles from the Courthouse in Bloomington. It
could have been placed in Thunder Bay, Washington D.C., New
Orleans, or even Oklahoma City, but we decided that 77 miles was
far enough. To give you a sense of perspective, the entire inner
solar system (including Mercury, Venus, Earth, Mars, and the asteroid belt) all fit within the city
limits of Bloomington, all the gas giants are within 20 miles, and
even Pluto never gets further than 34 miles away. Other than
comets, which are way too small for this scale, there's practically
nothing in the solar system that's known to be farther away than
Sedna.
It's so far out there, that the scientists who discovered it
decided to name it after the Inuit goddess of the sea, who lives at
the bottom of the Arctic Sea.
Our best guess as to the size of Sedna is that it's between
1,200 and 1,600 kilometers across so the model was built to be
about 0.4 inches across. Unlike most of of the dwarf planets, which
are more-or-less gray, Sedna has a dark red color.
There's a lot we don't know about Sedna, and a lot of
speculation about where it came from, what it's made of, why it's
so red, and the like. Only time and more data will tell us the
answers to its greatest mysteries.
The cache is placed near a restaurant with a long history.