Sutter's Mill meteorite

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Sutter's Mill meteorite
Sutter's Mill Meteorite.jpg
Fragments of the Sutter's Mill meteorite obtained from Henningsen Lotus Park, Lotus, California.[1]
Type Chondrite
Class Carbonaceous chondrite
Group CM2
Country USA
Region California
Coordinates 37°36′N 120°30′W / 37.6°N 120.5°W / 37.6; -120.5Coordinates: 37°36′N 120°30′W / 37.6°N 120.5°W / 37.6; -120.5 (airburst)[2]
38°48’14"N, 120°54’29"W[3]
Observed fall Yes
Fall date 22 April 2012
Found date 24 April 2012
TKW 952.7 grams[4]
Strewn field Yes
8.5 gram Sutter's Mill Meteorite.jpg
SM33 (8.5 g) fragment with a small part of the fusion crust missing[5]

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.[6][7] On 3 May 2012 scientists with the Ames Research Center and the SETI Institute utilized an airship to get aerial photography of the strewn field with the current vegetation that may help detect more fragments of the meteorite.[8] As of November 2012, 75 fragments have been publicly documented with a find location, and the largest (SM53) weighs 205 grams.[4][9] The second largest (SM50) only weighs 42 grams.[9]

The meteorite was found to contain some of the oldest material in the Solar System.[10][11][12]

The name comes from the Sutter's Mill, the California Gold Rush site near where some pieces were recovered.[3][13]

History[edit]

During the 2012 Lyrids meteor shower, a bolide and sonic boom rattled buildings in California and Nevada around 07:51 PDT 22 April 2012.[14] The bolide air burst was probably a random unrelated meteoroid and not a member of the Lyrids shower.[15] The bolide was so bright that witnesses were seeing spots afterward.[16] The event was recorded by two infrasound monitoring stations of the Comprehensive Nuclear-Test-Ban Treaty Organization’s International Monitoring System.[17] The preliminary analysis are indicative of energy yield of approximately 4 kilotons of TNT equivalent.[17] Hiroshima's "Little Boy" had a yield of about 16 kt. The meteoroid was probably between the size of a dish washer[18] and a mini van.[19] The air burst had approximate coordinates of 37°36′N 120°30′W / 37.6°N 120.5°W / 37.6; -120.5.[2] The falling meteorites were picked up by weather radar over an area centered on Sutter's Mill in Coloma, between Auburn, California, and Placerville, California.[7]

Robert Ward found a small CM chondrite fragment in the Henningsen Lotus Park just west of Coloma, CA on 24 April 2012.[20] Later that day, meteor astronomer 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. 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'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).[21]

Comparisons[edit]

The event is similar to the 1969 Murchison meteorite in Australia. The only two other witnessed meteorite falls in California with recovered fragments are Red Canyon Lake on 11 August 2007 and San Juan Capistrano on 15 March 1973.[22] Compared to this event's theorized 4 kilotons of TNT equivalent yield,[17] the Trinity nuclear test in New Mexico was about 18 kilotons of TNT equivalent[23] and "Little Boy" had a yield of about 16 kilotons of TNT equivalent in explosive force, i.e. 6.3 × 1013 joules = 63 TJ (tera-joules).[24]

Since the incoming meteoroid is estimated to have been 2–4 meters in diameter, the original meteoroid probably had an absolute magnitude (H) of roughly 31.[25]

Examples[edit]

See also[edit]

References[edit]

  1. ^ "APOD: 2012 April 28 - Sutter's Mill Meteorite". APOD. NASA & MTU. 2012-04-28. Retrieved 2012-04-28. 
  2. ^ a b Bill Cooke of NASA Meteoroid Environments Office (Apr 23, 2012). "(meteorobs) Fwd: large bolide over California/Nevada". Retrieved 2012-04-23. 
  3. ^ a b "Sutter's Mill". Lunar and Planetary Institute: Meteoritical Bulletin Database. Retrieved 2012-05-22. 
  4. ^ a b Mike Gilmer (June 27, 2012). "Sutter's Mill California Meteorite Fall - Tally of Known Finds". Retrieved 2012-07-07. 
  5. ^ Ruben Garcia. "Sutter Mill Meteorite Hunt". Mr-Meteorite. Retrieved 2012-05-09. 
  6. ^ Ian O'Neill (2012-04-23). "Minivan-sized Asteroid Exploded Over California". Discovery News. Retrieved 2012-04-28. 
  7. ^ a b Marc Fries (mfries01) (23 April 2012). "Coloma, CA 22 Apr 2012 1452 UTC". Radar Obs of Meteor Events. Retrieved 2012-04-25. 
  8. ^ "Scientists aboard airship to search for meteorites strewn over California gold country". Washington Post. May 3, 2012. Retrieved 2012-05-04. 
  9. ^ a b Peter Jenniskens. "The Impact and Recovery of the Sutter's Mill Meteorite". SETI Institute. Retrieved 2012-07-07. 
  10. ^ http://www.sciencenews.org/view/generic/id/347199/description/California_meteorite_a_scientific_gold_mine
  11. ^ http://www.nature.com/news/us-meteorite-was-fastest-on-record-1.12095
  12. ^ http://www.businessinsider.com/one-of-the-fastest-rarest-meteorites-recovered-in-californias-gold-county-2012-12
  13. ^ Franck Marchis (April 25, 2012). "Fragments of the daylight meteor found in California". Cosmic Diary. Retrieved 2012-04-26. 
  14. ^ Guy Clifton (Apr 22, 2012). "Meteor shower likely cause of big boom heard throughout region". Reno Gazette-Journal. Retrieved 2012-04-22. 
  15. ^ Deborah Byrd (Apr 22, 2012). "Loud boom and bright fireball over California and Nevada on April 22". EarthSky. Retrieved 2012-04-22. 
  16. ^ Guy Clifton (Apr 23, 2012). "Local resident's photo of Sunday's meteor goes international". Reno Gazette-Journal. Retrieved 2012-04-23. 
  17. ^ a b c Guy Clifton (Apr 23, 2012). "Scientist says sound signal from exploding meteor lasted 18 minutes". Reno Gazette-Journal. Retrieved 2012-04-23. 
  18. ^ "Explosion Heard in NV, CA Traced To Meteor". KTVN 2 (Reno). Apr 22, 2012. Retrieved 2012-04-23. 
  19. ^ "Fireball Over California/Nevada: How Big Was It?". NASA/JPL. April 24, 2012. Retrieved 2012-04-24. 
  20. ^ Franck Marchis (Apr 25, 2012). "Re: {MPML} Fireball Over California/Nevada: How Big Was It?". Yahoo group: Minor Planet Mailing List (mpml). Retrieved 2012-04-25. 
  21. ^ "Sutter's Mill Meteor". Gold Discovery Park Association. Retrieved 2012-05-04. 
  22. ^ Peter Jenniskens (May 25, 2009). "California Meteorite Falls". SETI Institute. Retrieved 2012-04-30. 
  23. ^ Richard Rhodes, The Making of the Atomic Bomb (New York: Simon and Schuster, 1986), pp. 677.
  24. ^ Los Alamos National Laboratory report LA-8819[dead link], The yields of the Hiroshima and Nagasaki nuclear explosions by John Malik, September 1985.
  25. ^ "Conversion of Absolute Magnitude to Diameter". Minor Planet Center. Retrieved 2012-05-30. 

External links[edit]