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Basic information Name: Komaki
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: Yes, confirmed fall
Year fell: 2018
Country: Japan
Mass:help 650 g
Meteoritical Bulletin:  MB 108  (2020)  L6
Recommended:  L6    [explanation]

This is 1 of 12995 approved meteorites (plus 11 unapproved names) classified as L6.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 16 Feb 2019
Writeup from MB 108:

Komaki        35°18’38"N, 136°56’59"E

Chubu, Japan

Confirmed fall: 2018 Sep 26

Classification: Ordinary chondrite (L6)

History: Around 22:30 on September 26, 2018, a detonating sound was heard at a private house in Komatsuji, Komaki city, Aichi prefecture, Japan. No fireball was observed because of the cloudy weather, with intermittent rain. Next morning, several fragments including 81 g and 23 g were found on the roof and in the garden. A 550 g mass was also found at the next-door house. The meteorite apparently hit the roof, bounced to the next house, penetrated the roof of the carport, and hit the roof of the car. It finally came to rest in front of the entrance door. The meteorite was brought to NMNS on October 6, where cosmogenic Na-22 and Al-26 gamma rays were detected by the pure Ge detector.

Physical characteristics: The 550 g mass is a rounded disk shape. One side is fully covered by fusion crust and the other is about half covered. The 81 g and 23 g fragments fit together with the 550 g mass, hence the meteorite was one mass that fragmented due to the impact on the roof.

Petrography: A polished thin section and a polished mount were made from a 1 g fragment at NIPR. Olivine compositions are Fa23.9-25.5 (mean Fa24.7, N=31), and low-Ca pyroxene compositions are Fs20.0-21.3 (mean Fs20.7, N=19). The presence of plagioclase >50 μm indicates that the petrologic type is 6. The presence of mottled extinction and planar fractures in olivine indicates that the shock stage is S3.

Geochemistry: Using a 50 mg fragment, rare gas analyses were made at KyuU. The Ne-21 cosmic-ray exposure age is 25.1±0.6 Ma, and the K-Ar gas retension age is 4.4±0.2 Ga.

Classification: L6

Specimens: NMNS: 81 g for display, 20 g for type specimen; NIPR: 1 polished thin section, 1 polished mount

Data from:
  Table 0
  Line 0:
Date:2018 Sep 26
Mass (g):650
Shock stage:S3
Fayalite (mol%):24.7 (23.9-25.5, N=31)
Ferrosilite (mol%):20.7 (20.0-21.3, N=19)
Classifier:A. Yamaguchi, NIPR; M. Kimura, NIPR; R. Okazaki, KyuU; S. Yoneda, NMNS
Type spec mass (g):20
Type spec location:NMNS
Main mass:Finder (on loan for display at NMNS and later at the Nagoya City Science Museum)
Comments:Submitted by S. Yoneda, NMNS
   and collections
NIPR: Antarctic Meteorite Research Center, National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan; Website (institutional address; updated 9 Dec 2013)
NMNS: National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, JAPAN, Japan; Website (institutional address; updated 16 Jun 2014)
KyuU: Department of Earth and Planetary Science, Kyushu University Hakozaki, Higashi-ku, Fukuoka-shi 812- 8581, Japan (institutional address)
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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Public domain photographs:
Shigekazu Yoneda      

     Recommended::   (35° 18' 38"N, 136° 56' 59"E)

     This is 1 of 14 approved meteorites from Chubu, Japan (plus 2 unapproved names)
     This is 1 of 58 approved meteorites from Japan (plus 12 unapproved names)
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