New Delhi, Oct. 7 -- A 10.22-kilogram rock that spent decades holding open a barn door on a Michigan farm has been identified as an iron meteorite from the IIIAB group. The Meteoritical Bulletin reports that the rock was seen falling near Edmore, Michigan, in 1939, and was subsequently recovered on a farm. The official database has now changed the status of the fall of 1939 to doubtful.

It remained on the farm for decades, and the meteorite was used as a doorstop. Following another meteorite impact in nearby Hamburg, Michigan, in early 2018, the subsequent farmer rethought the unusual rock and brought it to Central Michigan University (CMU) in Mount Pleasant for identification.

A sample was then sent to the Smithsonian Institution for f...