The shape of meteorites

• Main Author: Hasegawa, Hiroichi
• Language: English
• Published: 1981
• Subjects: Yamato; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/record/1223/files/KJ00000011749.pdf

P(論文) The shape of meteorites is described by axial ratio (b/a), where a and b are the longest and the intermediate axial lengths of meteorite, respectively. Used samples are the Yamato meteorites recovered in 1973-1975. Distribution of (b/a) and the average value of 0.730 of 930 chondrites except carbonaceous ones are obtained. The results are similar to those of basalt fragments in laboratory impact experiment. Five chondrite showers are also analyzed. Their mass spectra are well represented by power function of fragment mass with the exponents α of 0.95±0.05,0.60±0.05,3.0±0.4,2.5±0.1 and 3.5±0.3. With the assumptions that each shower originated in a single impact, the produced fragments are not lost and the high velocity impact law found by laboratory experiment is applicable to meteorite showers, these showers are of the "core type" destruction with impact energies per unit target mass of (10)^7 erg/g-(10)^8 erg/g. Distributions of (b/a) and the average values of each shower resemble each other and also those of all chondrites. Among about 40 achondrites, 29 diogenites belong to one shower with rounded fragment ( =0.794) and flat mass spectrum (α=0.35+0.02). departmental bulletin paper