Class named after the Mighei meteorite that fell in Ukraine in 1889. CM meteorites are generally petrologic level type 2, have about half the water content of CI chondrites, show less aqueous alteration, and retain some well-preserved small chondrules (diameter s <0.5 mm; 10-40 vol. %) and CAIs (~5 vol. %). Like CIs, however, they contain a wealth of organic material: more than 230 different amino acids have been identified in the Murchison meteorite. Comparisons of spectra point to the asteroid 19 Fortuna or, possibly, the largest asteroid, 1 Ceres, as candidate parent bodies.
Some or all content above used with permission from J. H. Wittke.