This is a long-exposure shot of an aurora borealis by Ole Christian Salomonsen in TromsÃ¸, Norway. Personally, I think it looks like a giant alien woman in a loose-fitting robe shying away from the camera, but that might just be the weed talking. Ooooor because she's embarrassed her vagina's green.
Auroras emit light because of the emission of photons by oxygen and nitrogen atoms in the upper atmosphere. Those atoms get excited--or ionized--by the collision with solar wind particles, which are accelerated by the Earth's magnetic field. As the atoms get excited or return to their normal state, they emit visible energy. When it is an oxygen atom, the light emitted is either green or brownish-red, depending on the energy level absorbed by the molecule. Blue happens when nitrogen gets ionized, and red when it returns to ground state.
Beautiful, isn't it? I swear, Mother Nature never ceases to amaze me. And I'm not saying that because I once saw a squirrel jump out of a tree holding a balloon, but I did and I don't think it slowed him down as much as he thought it would. Short story short: he broke a leg and I had to finish him off with a shovel.
Thanks to Justin, who once saw a squirrel humping an empty soda can at the park. Nuh-uh! What kind of noise did it make?