See, you are already confused: it's Sol/Terra/Luna, descending order by diameter. One is tempted to put the Sun and the Moon before the Earth, as those are "celestial".
So, Terra should work for most "down-to-earth" problems, Luna is for light-weight stuff (because less gravity?), and if you really want to burn tokens like there's no tomorrow, you go for the fusion furnace at the center of our solar system?