In honor of the planet we call our bitch, the Denver Museum of Nature and Science is holding a free day on Sunday, opening its doors to everybody who wants to come in and look at the stuff they've got, like the display of Egyptian mummies, or Expedition Health (which is actually really cool -- you take out a card that compiles information about you while you do different activities, like ride a stationary bike), or Space Odyssey, which is probably the least Earth-ish thing there, but is still pretty awesome because it's about outer space. It's also an excellent time to check out the Real Pirates exhibit, if you haven't done that yet, which is not free, but tickets are on sale at a reduced rate of $8 adult (they're normally $22).
So go ahead, Earth. Treat yourself. This is your day.