The rocks each weighed about 10 grams, or the weight of two nickels, said John T Wasson, a longtime professor and expert in meteorites at UCLA's Institute of Geophysics and Planetary Physics.
Experts say the flaming meteor, dating to the early formation of the solar system 4 to 5 billion years ago, was probably about the size of a minivan when it entered the Earth's atmosphere with a loud boom early Sunday. It was seen from Sacramento, California, to Las Vegas and parts of northern Nevada.
An event of that size might happen once a year around the world, said Don Yeomans of Nasa's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California. But most of them occur over the ocean or an uninhabited area, he said.