The Sutter's Mill meteorite is a

carbonaceous chondrite Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small propo ...

which entered the Earth's

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

and broke up at about 07:51

Pacific Time The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00). ...

on April 22, 2012, with fragments landing in the United States. The name comes from

Sutter's Mill Sutter's Mill was a water-powered sawmill on the bank of the South Fork American River in the foothills of the Sierra Nevada in California. It was named after its owner John Sutter. A worker constructing the mill, James W. Marshall, found go ...

, a

California Gold Rush The California gold rush (1848–1855) began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California from the rest of the U ...

site, near which some pieces were recovered. Meteor astronomer

Peter Jenniskens Petrus Matheus Marie (Peter) Jenniskens (born 1962 in Meterik) is a Dutch- American astronomer and a senior research scientist at the Carl Sagan Center of the SETI Institute and at NASA Ames Research Center. He is an expert on meteor showers, a ...

assigned Sutter's Mill (SM) numbers to each

meteorite A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...

, with the documented find location preserving information about where a given meteorite was located in the impacting meteoroid. As of May 2014, 79 fragments had been publicly documented with a find location. The largest (SM53) weighs , and the second largest (SM50) weighs . The meteorite was found to contain some of the oldest material in the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

. Two 10-micron diamond grains (

xenolith A xenolith ("foreign rock") is a rock (geology), rock fragment (Country rock (geology), country rock) that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term ''xenolith'' is almost exclusi ...

s) were found in meteorite fragments recovered before any rain fell as the rain would degrade the purity of the meteorites for scientific study. 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.

History

During the 2012

Lyrids The April Lyrids are a meteor shower lasting from about April 15 to April 29 each year. The Radiant (meteor shower), radiant of the meteor shower is located near the constellations Lyra and Hercules (constellation), Hercules, near the bright sta ...

meteor shower, a

bolide A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large Impact crater, crater-forming body, or to one that explodes in the atmosphere. ...

and

sonic boom A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to ...

rattled buildings in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

in daylight conditions in the early morning at 07:51 PDT on 22 April 2012. The

meteor air burst A meteor air burst is a type of air burst in which a meteoroid explodes after entering a planetary body's atmosphere. This fate leads them to be called fireballs or bolides, with the brightest air bursts known as superbolides. Such meteoroids w ...

was caused by a random

meteoroid A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classifie ...

, not a member of the Lyrids shower. The bolide was so bright that witnesses were seeing spots afterward. The falling meteorites were detected by

weather radar A weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation (meteorology), precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern w ...

over an area centered on the Sutter's Mill site in Coloma, between

Auburn, California Auburn is a city in and the county seat of Placer County, California, United States. Its population was 13,776 during the 2020 United States census, 2020 census. Auburn is known for its California Gold Rush history and is registered as a Califo ...

, and

Placerville, California Placerville (, ; ''placer'', Spanish for "sand deposit", representing the placer mining that was predominant in the town's development, and ''ville'', French for "town") is a city in and the county seat of El Dorado County, California, United S ...

. Robert Ward found a small C chondrite fragment in the Henningsen Lotus Park just west of Coloma, CA on 24 April 2012. Later that day,

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. These were the only meteorites found before rain hit the area on 25 April. On 1 May 2012, the James W.

Marshall Gold Discovery State Historic Park Marshall Gold Discovery State Historic Park is a state park of California, United States, marking the discovery of gold by James W. Marshall at Sutter's Mill in 1848, sparking the California Gold Rush. The park grounds include much of the histo ...

's ranger Suzie Matin discovered two pieces of the meteorite (SM14 @ 11.5 grams) in her front yard. The park contains what is now known as Sutter's Mill (site). On 3 May 2012 scientists with the

Ames Research Center The Ames Research Center (ARC), also known as NASA Ames, is a major NASA research center at Moffett Federal Airfield in California's Silicon Valley. It was founded in 1939 as the second National Advisory Committee for Aeronautics (NACA) laborat ...

and the

SETI Institute The SETI Institute is a not-for-profit research organization incorporated in 1984 whose mission is to explore, understand, and explain the origin and nature of life in the universe, and to use this knowledge to inspire and guide present and futu ...

utilized an

airship An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying powered aircraft, under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the ...

to search the

strewn field A strewn field is the area where meteorites from a single meteorite fall, fall are dispersed. It is also often used for the area containing tektite, tektites produced by a large meteorite impact.''Tektites in the geological record: showers of glas ...

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 The Murchison meteorite is a meteorite that fell in Australia in 1969 near Murchison, Victoria. It belongs to the carbonaceous chondrite class, a group of meteorites rich in organic compounds. Due to its mass (over ) and the fact that it was ...

fall. Ground-based searches resulted in the additional recovery of two pristinely collected meteorites (SM12 and SM67) for scientific study.

Comparisons

This is the third witnessed

meteorite fall A meteorite fall, also called an observed fall, is a meteorite collected after its fall from outer space, that was also observed by people or automated devices. Any other meteorite is called a "meteorite find, find". There are more than 1,300 d ...

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. A consortium of over 50 scientists investigated the circumstances of the impact and the properties of the meteorites. The event was recorded by two

infrasound Infrasound, sometimes referred to as low frequency sound or incorrectly subsonic (subsonic being a descriptor for "less than the speed of sound"), describes sound waves with a Audio frequency, frequency below the lower limit of human audibility ...

monitoring stations of the

Comprehensive Nuclear-Test-Ban Treaty Organization The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is an international organization that will be established upon the entry into force of the Comprehensive Nuclear-Test-Ban Treaty, a Convention that outlaws nuclear test explosions. I ...

’s International Monitoring System. The preliminary analyses are indicative of an energy yield of approximately four kilotons of TNT equivalent. Hiroshima's "

Little Boy Little Boy was a type of atomic bomb created by the Manhattan Project during World War II. The name is also often used to describe the specific bomb (L-11) used in the bombing of the Japanese city of Hiroshima by the Boeing B-29 Superfortress ...

" had a yield of about 16 kt. The air burst had approximate coordinates of . Based on the infrasound signal and the brightness of the fireball in photographs and two video records, the incoming meteoroid was estimated to have been in diameter, between the size of a

dishwasher A dishwasher is a machine that is used to clean dishware, cookware, and cutlery automatically. Unlike dishwashing, manual dishwashing, which relies on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot wat ...

and a

minivan Minivan (sometimes called simply a van) is a car classification for vehicles designed to transport passengers in the rear seating row(s), with reconfigurable seats in two or three rows . The equivalent classification in Europe is MPV (multi-p ...

. Before entry in Earth's atmosphere, the meteoroid probably had an absolute magnitude (H) of roughly 31. The meteoroid entered at a record speed of , the fastest fireball on record from which meteorites were later recovered. It broke apart at an altitude of , the highest breakup event on record resulting in meteorites on the ground. Before entry, the meteoroid moved on an eccentric orbit, stretching from just inside the orbit of Jupiter to the orbit of Mercury. The orbit had a shallow inclination and an orbital period suggesting that this meteoroid originated in the 3:1 mean motion resonance with Jupiter. The CM chondrite

Maribo Maribo is a town in Lolland Municipality in Region Zealand, Region Sjælland on the island of Lolland in south Denmark. It was the municipal seat of the former Maribo Municipality, until 1 January 2007, and then it became the seat of the cur ...

moved on a similar orbit, but rotated by 120 degrees in the direction of the line of

apsides An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

. 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 meteorite type is similar to that of the 1969

in Australia. Unlike Murchison, Sutter's Mill shows clear brecciation: fragments of CM lithologies with different aqueous alteration and thermal processing histories are embedded in a fine grained CM matrix material. The Sutter's Mill meteorite originated from near the surface of its parent body. As a whole, Sutter's Mill is harder than Murchison. The pre-rain collected meteorite SM2 was found to contain the mineral

oldhamite Oldhamite is a calcium magnesium sulfide mineral with the chemical formula . Ferrous iron may also be present in the mineral resulting in the chemical formula . It is a pale to dark brown accessory mineral in meteorites. It crystallizes in the cub ...

(CaS), a mineral that reacts readily with water vapor. This

ic material may have come from

enstatite Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and m ...

chondrites impacting on the surface of the CM chondrite parent body in the past. The Sutter's Mill meteorite is used to test sample collection and analysis procedures for NASA's

OSIRIS-REx OSIRIS-REx was a NASA asteroid-study and sample-return mission that visited and collected samples from 101955 Bennu, a C-type asteroid, carbonaceous near-Earth object, near-Earth asteroid. The material, returned in September 2023, is expected ...

sample return mission.

Examples

File:Sm39-Miller-2 5g.JPG, SM39 (2.5 g) File:SM-Miller-5.9g.jpg, Mike Miller's SM49 (5.9 g)

References

External links

California Meteor Broke Speed Record for Atmospheric Entry
(

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...

December 20, 2012)
Sutter's Mill Meteorite: a Californian Treasure Discovered by SETI/NASA Researchers
( Google Hangout chat 20 December 2012) *
Analysis of Sutter's Mill fragments reveals organic compounds not seen in other meteorites
(Phys.org : 10 Sept 2013)

(Mr-Meteorite Ruben Garcia purchased 8.5 gram Sutter Mill Meteorite with broken fusion crust)
Patient hunters find more meteorites from California fall
(AstroBob April 29, 2012)
Robert Wards 44 gram findSteve Arnold (meteorhntr) photos of 0.38g SM slice
(oriented 9.9g)
Sutter's Mill photos at ASU
(SM6, SM8, SM38, SM41, SM49
Video of the daylight California fireball
(Phil Plait 31 May 2012)
CAMS
News blog (CAMS is an automated video surveillance of the night sky in search of meteors to validate minor showers in the IAU Working List of Meteor Showers) *

Strewn field A strewn field is the area where meteorites from a single meteorite fall, fall are dispersed. It is also often used for the area containing tektite, tektites produced by a large meteorite impact.''Tektites in the geological record: showers of glas ...

maps:
Coloma, CA Strewn Field Map
(Marc Fries) **Sutter Mil
strewn field
(Jim Wooddell)

(SacBee: Last Modified: Monday, May. 7, 2012)
Sutter Mill Meteorite Find Tally
(An updated tally of Sutter Mill meteorites found - Mike Gilmer)
Official Sutter Mill Meteorite Hunt Page - NASA/SETI
(Dr. Jenniskens' Official Sutter Mill Find Data Page) {{2012 in space Meteorites found in the United States Modern Earth impact events 2012 in outer space 2012 in California Geology of California April 2012 in the United States 21st-century astronomical events

History

Comparisons

Examples

See also

References

External links