Pluto

The Dwarf Among Us Planet or not, Pluto is a harsh environment. Certainly more than a moon, Pluto actually has an atmosphere, and it's infused with traces of explosive nitrogen compounds that form from high-energy cosmic rays exciting the abundant carbon monoxide and nitrogen. You should use this chemical energy, since solar is completely impractical. Even the air itself seems frozen in stillness, as storms never stir. Oxygen is strangely hard to come by, but if you can power your Plutonian greenhouse in time, this won't be an issue. More Details 1. Slightly less solar energy than even Mimas 2. Atmos is mostly nitrogen, with some CO2, and even less N2O 4. No oxite 5. Hydrocarbons do freeze on the surface (coal and volatiles) 6. Very cold (40-60K) 7. Purple rocks