Menisa        53°26.648’N, 113°27.244’W

Alberta, Canada

Probable fall: October 2022

Classification: Ordinary chondrite (L6)

History: Mr. Doug Olson heard a loud bang on the roof of his house, in the Menisa neighborhood of Edmonton, one afternoon in October 2022 while in an upstairs room. On the same day he went onto the roof looking for damage searching for the source of the noise, but found nothing at the time. On May 20, 2023 he was cleaning debris from the eaves and found a single, 33.3 g mass in the eavestrough. The specimen was brought to UAb on May 31, 2023 where it was identified as a meteorite.

Physical characteristics: The single mass is approximately 60% covered in dark fusion crust. Some minor iron staining is present around metal grains near the outer surface.

Petrography: (C. Herd, UAb) Optical and microprobe examination of a polished thin section shows a thin, fresh fusion crust the entire circumference of the thin section, with a <500 µm heat-affected zone. The texture is brecciated, with poorly defined chondrules. Minor iron staining is present only near the exterior. Olivine shows weak mosaicism and planar fractures; plagioclase is crystalline.

Geochemistry: (C. Herd and A. Locock, UAb) Data obtained by EMP examination of carbon-coated thin section: Olivine Fa_24.7±0.3 (n=35); Low-Ca Pyroxene Fs_20.7±0.1Wo_1.5±0.1 (n=21).

Classification: Ordinary chondrite, L6 breccia

Specimens: Type specimen of 7.9 g, including one polished thin section, at UAb. Main mass with Mr. Doug Olson.