Friday, December 21, 2007

Friday beautiful science


Today's Friday beautiful science comes from the Sandia National Labs. It's a simulation of the meteorite impact in Russia in the early part of the 20th century. This new simulation allows all kinds of predictions about the size and shape of the impacting object, and allows us to predict the frequency of such events:

The stunning amount of forest devastation at Tunguska a century ago in Siberia may have been caused by an asteroid only a fraction as large as previously published estimates, Sandia National Laboratories supercomputer simulations suggest.

“The asteroid that caused the extensive damage was much smaller than we had thought,” says Sandia principal investigator Mark Boslough of the impact that occurred June 30, 1908. “That such a small object can do this kind of destruction suggests that smaller asteroids are something to consider. Their smaller size indicates such collisions are not as improbable as we had believed.”

Because smaller asteroids approach Earth statistically more frequently than larger ones, he says, “We should be making more efforts at detecting the smaller ones than we have till now.”

The new simulation — which more closely matches the widely known facts of destruction than earlier models — shows that the center of mass of an asteroid exploding above the ground is transported downward at speeds faster than sound. It takes the form of a high-temperature jet of expanding gas called a fireball.
Head on over there. There are all kinds of movies to watch, and their detailed description is pretty fun.


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