The things that most excited me about geology and paleobiology are included in this story, most of things I didn’t much care for aren’t. A solid read. Seriously:

Theia hits the Earth and shears off a large chunk, forming a trail of shattered, molten or vaporized rock that arcs off into space. Within an hour, half the Earth’s surface is red-hot, and the trail of debris stretches almost 4 Earth radii into space. After 3 to 5 hours, the iron core of Theia and most of the the debris comes crashing back down. The Earth’s entire crust and outer mantle melts. At this point, a quarter of Theia has actually vaporized!

(via kottke)