Secrets of Wisconsin meteorite revealed

As Russian scientists scramble to collect and analyze the remains of the historic meteorite that injured an estimated 1,200 people in Chelyabinsk on Feb. 15, scientists in Wisconsin are set to publish their analysis of a smaller meteorite that struck southwest Wisconsin on April 14, 2010. The Mifflin meteorite created a fireball equivalent to 20 tons of TNT, initiating a scientific quest that revealed the complex history of a rocky body that predates Earth's formation. Although the fireball could be seen from Madison, 50 miles away, the meteorite was far smaller than the object that exploded over Siberia. In Wisconsin, about eight pounds of fragments were recovered from an object that probably weighed a few tons before it struck the atmosphere, says John Valley , a professor of geoscience at UW-Madison. "It was a gold rush for about a week, like the Wild West, as residents and meteorite hunters from around the world scoured the area." Although fragments could be sold to collectors, "many Wisconsinites were generous enough to donate and allow us to analyze the samples they collected," says Valley. Using a variety of sophisticated instruments located at the Department of Geoscience and other labs in the United States, Switzerland and Italy, the scientists identified the stony meteorite as an L5 chondrite.