Our planet produces many spectacular light shows, such as aurorae (Borealis & Australis), ball lightning (including the super awesome atmospheric lighting), and the odd meteor shower. I would give certain appendages to be able to witness these in the flesh, but none more so than the splendidly epic Sundogs.
Sundogs appear to the left and right of the sun, best viewed when during sunrise or sunset. This effect is also referred to as a mock sun, due to the fact it appears to show three suns in the better examples. Unlike aurorae, sundogs can be viewed all over the world, although they are rare. So there’s a semi-good chance of viewing one, which makes me happy.
This natural phenomenon is a byproduct of hexagonal ice crystals, curiously named diamond dust (or more scientifically called clear-sky precipitation), which under certain conditions cause the effect.
What actually causes this is a bit beyond me, but the basic principle is that of refraction. Detailed explanation of sundogs can be found on Wikipedia and for those not interested in reading too much mumbo jumbo, like myself, here is a diagram of how it all works.
Some juicy photographs of this spectacle after the jump.