Want a preview of what would happen if an asteroid 500 kilometers in diameter slammed into Earth? In 2005, the National Film Board of Canada teamed up with Japan’s NHK to produce Miracle Planet, a science documentary detailing the life of our planet. Part of the series was the above simulation of an asteroid impact, which was created with a great deal of scientific input.
This video is taken out of the context of the film, and backed by Pink Floyd’s “Great Gig in the Sky.” The lack of narration combined with the song selection makes the footage eerie beyond compare. (Do download it in 720p and watch it fullscreen.)
Here’s what you’re seeing:
The asteroid impacts the Pacific Ocean south of Japan. The energy of that impact peels up the Earth’s crust, sending it into space in an expanding ring as the shockwave (both ocean and crust) travels outward. It’s still strong enough upon hitting Japan to disintegrate the entire island archipelago, as well as part of the Asian coast.
The molten material that had been sent spaceward now falls back onto Earth, courtesy of the planet’s strong gravity. The crater, now full of molten rock, is edged by a rim 7,000 meters high. It is 4,000 kilometers in diameter.
The real issue, however, is the rock vapor. The massive energy delivered by the asteroid’s impact has superheated the crust to such an extent (equaling the temperature on the surface of the sun) that it creates a literal firestorm, which rapidly expands to cover the entire planet. In other words, what the impact didn’t destroy, the rock vapor cloud will. Upon reaching the Himalayas, it instantly evaporates all snow. The glaciers take slightly longer. Eventually the oceans boil away, leaving no liquid water on Earth. Within one month after impact, the planet is completely sterilized.
Scientists think this happened to our planet six times in its early history.
What the excerpt doesn’t show is the refilling of the oceans, lakes and rivers courtesy of massive, unending rainstorms, which occur once the atmosphere has cooled enough to allow condensation of all that water vapor. The stage is set for life to start all over again — but from what?
If you’d like to see this footage in the context of the documentary, with the narration, go here and start around 2:25. But I’d recommend watching the whole episode, which is posted in four parts starting here. And then you’ll learn something extremely cool about how life could have survived an apocalypse like that.
(via Bad Astronomy, eons ago)