See that slant in the Earth's terminator line as day turns to night? It's a product of the Earth's tilt — and a beautiful illustration of why the Northern Hemisphere gets so much less sunlight in December.
Last night was the darkest night in hundreds of years. Did you miss it? Watch this amazing time-lapse video of the entire event.
Late Monday night—well, actually, early Tuesday morning—the moon will move into the earth's shadow, causing a lunar eclipse visible to anyone in North America. Even better, it's happening on the Winter Solstice, for the first time since 1638.