
Meteorite expert and researcher Peter Jenniskens with a fragment of the bolide seen over California on April 22, 2012.
Jenniskens went out searching and found a four-gram fragment of the meteor in a parking lot in Lotus, California.
Update: NASA and the SETI Institute are asking the public to submit any amateur photos or video footage of the meteor that illuminated the sky over the Sierra Nevada mountains and created sonic booms that were heard over a wide area at 7:51 a.m. PDT Sunday, April 22, 2012.
Marchis wrote that several scientists from the Bay Area met at NASA Ames Research Center on April 24 to discuss a strategy for a search campaign, examining a radar data map which showed that dozens of fragments from the 100g to 1 kg range may have reached the ground.
Jenniskens said the fragment he found was a Carbonaceous Chondrites from the CM group of meteorites, "a rare type of primitive meteorite rich in organic compounds," he said.
"We are very interested in this rare find," said Greg Schmidt, deputy director of the NASA Lunar Science Institute. "With the public's help, this could lead to a better understanding of these fascinating objects."
Several other fragments were found, the first one by noted meteorite hunter Robert Ward.
"Getting fresh fragments of meteoroids, called meteorites, is key for astronomers to understand the composition of those remnants of the formation of the solar system," Marchis wrote. "Fresh fragments are unaltered by the Earth's weather and erosion processes, so they are pristine samples which can be used to detect organic materials for instance."
Photos and video footage would help the scientists to better analyze the trajectory of the meteor and learn about its orbit in space. This information will also help scientists to locate the places along the meteor path where fragments may have fallen to the ground.
People who have photos or video of the meteorite are asked to contact Jenniskens at petrus.m.jennniskens@nasa.gov.
Marchis noted that a storm is heading towards the region and rain could alter the remaining fragments. So if you live nearby, consider heading out to take a look. Here is the radar map:

Radar map by Marc Fries showing the possible location of fragments (green area) of the meteor between Auburn and Placerville.
Read more at the Cosmic Diary.