News24

Scientists search for meteorites

2012-05-04 11:26

Sacramento - A group of scientists took to the skies in a blimp on Thursday in search of meteorites that rained over California's gold country in April.

It's the latest hunt for extraterrestrial fragments from the April 22 explosion that was witnessed over a swath of Northern California and Nevada.

Treasure hunters have swarmed the Sierra Nevada foothills over the past two weeks, snatching up pieces of meteorites. Most of the recovered space rocks have been tiny, with the largest weighing in at 19g, or the weight of one AA battery.

Researchers from Nasa and the non-profit Seti Institute in Mountain View, California, were on the lookout for larger fragments. After a brief weather delay, they took off from a Sacramento airfield aboard a blimp outfitted with sensors and cameras.

From the air, scientists scoured the terrain for places where sizable meteorites might have scattered. The survey took them over the area where James W Marshall first discovered gold in California in 1848. Once they pinpoint possible impact sites, they plan to follow up with a search party.

Explosive power

"Only small pieces have been found. There has to be big pieces out there," Seti Institute meteor astronomer Peter Jenniskens said before the trip. "We're just hoping to collect more meteorites for research."

Days after the approximately 70 000kg meteor plunged through Earth's atmosphere with a loud sonic boom that was heard from Sacramento to Las Vegas, Jenniskens organised a team and found a 4g meteorite in the parking lot of a park.

Nasa estimated the minivan-sized meteor released energy equal to one-third the explosive power of the atomic bomb dropped on Hiroshima during World War II. An event this size occurs once a year usually over unpopulated areas.

Initial inspection of rock fragments indicates this type of meteorite is among the oldest, dating to the solar system's birth four billion to five billion years ago.