![]() The asteroid family that is the source region of CM chondrite-type meteorites is now thought to be located close to the 3:1 mean motion resonance, in low-inclined orbits, and may be the Eulalia asteroid family. The CM chondrite Maribo moved on a similar orbit, but rotated by 120 degrees in the direction of the line of apsides. The orbit had a shallow inclination and an orbital period suggesting that this meteoroid originated in the 3:1 mean motion resonance with Jupiter. It broke apart at an altitude of 157,000 ft (48 km), the highest breakup event on record resulting in meteorites on the ground.īefore entry, the meteoroid moved on an eccentric orbit, stretching from just inside the orbit of Jupiter to the orbit of Mercury. The meteoroid entered at a record speed of 64,000 ± 1,600 mph (28.6 ± 0.7 km/s), the fastest fireball on record from which meteorites were later recovered. Before entry in Earth's atmosphere, the meteoroid probably had an absolute magnitude (H) of roughly 31. īased on the infrasound signal and the brightness of the fireball in photographs and two video records, the incoming meteoroid was estimated to have been 6.6–13.1 feet (2–4 m) in diameter, between the size of a dish washer and a mini van. Hiroshima's " Little Boy" had a yield of about 16 kt. The preliminary analyses are indicative of an energy yield of approximately four kilotons of TNT equivalent. The event was recorded by two infrasound monitoring stations of the Comprehensive Nuclear-Test-Ban Treaty Organization’s International Monitoring System. Ī consortium of over 50 scientists investigated the circumstances of the impact and the properties of the meteorites. This is the third witnessed meteorite fall in modern California, following Red Canyon Lake on 11 August 2007 and San Juan Capistrano on 15 March 1973, while a few months after this event the Novato meteorite fell on 17 October 2012. Ground-based searches resulted in the additional recovery of two pristinely collected meteorites (SM12 and SM67) for scientific study. On scientists with the Ames Research Center and the SETI Institute utilized an airship to search the strewn field for the impact scars of kg-sized meteorites, but it is now understood that the high entry speed prevented the survival of meteorites as large as found in the Murchison meteorite fall. The park contains what is now known as Sutter's Mill (site). Marshall Gold Discovery State Historic Park's ranger Suzie Matin discovered two pieces of the meteorite (SM14 11.5 grams) in her front yard. These were the only meteorites found before rain hit the area on 25 April. Later that day, Peter Jenniskens found a crushed 4 g meteorite in the parking lot of that same park and Brien Cook found a 5 g meteorite off Petersen Road in Lotus. Robert Ward found a small CM chondrite fragment in the Henningsen Lotus Park just west of Coloma, CA on 24 April 2012. The falling meteorites were detected by weather radar over an area centered on the Sutter's Mill site in Coloma, between Auburn, California, and Placerville, California. The bolide was so bright that witnesses were seeing spots afterward. The meteor air burst was caused by a random meteoroid, not a member of the Lyrids shower. In primitive meteorites like Sutter's Mill, some grains survived from what existed in the cloud of gas, dust and ice that formed the Solar System.ĭuring the 2012 Lyrids meteor shower, a bolide and sonic boom rattled buildings in California and Nevada in daylight conditions in the early morning at 07:51 PDT on 22 April 2012. Two 10-micron diamond grains ( xenoliths) were found in meteorite fragments recovered before any rain fell as the rain would degrade the purity of the meteorites for scientific study. The meteorite was found to contain some of the oldest material in the Solar System. The largest (SM53) weighs 205 grams (7.2 oz), and the second largest (SM50) weighs 42 grams (1.5 oz). As of May 2014, 79 fragments had been publicly documented with a find location. Meteor astronomer Peter Jenniskens assigned Sutter's Mill (SM) numbers to each meteorite, with the documented find location preserving information about where a given meteorite was located in the impacting meteoroid. The name comes from Sutter's Mill, a California Gold Rush site, near which some pieces were recovered. The Sutter's Mill meteorite is a carbonaceous chondrite which entered the Earth's atmosphere and broke up at about 07:51 Pacific Time on April 22, 2012, with fragments landing in the United States. SM33 (8.5 g) fragment with a small part of the fusion crust missing
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