1581
Sea Level
(imgs.xkcd.com)
Alt text: They're up there with coral islands, lightning, and caterpillars turning into butterflies.
Oh for sure. The universe is too big for it to not have happened elsewhere. I’m not saying it’s unique, just rare.
For me, it was the fact that the Earth is tilted at just the right angle that sort of blew my mind. Too much one way or another, we wouldn’t have seasons or day/night cycles.
From under, other planets have been identified with the potential for life, but don’t have the tilt or the moon.