Aubrites are named for the Aubres meteorite that fell in 1836 near Nyons, France. They are an evolved achondrite that is Ca-poor and composed mainly of enstatite (En100) and diopside (En50Wo50) with minor amounts of olivine (Fa0) and traces of plagioclase (An2-8). They contain large white crystals of enstatite as well as small, varying amounts of olivine, Ni-Fe metal, troilite, and a variety of exotic accessory minerals, pointing to a magmatic origin under highly reducing (oxygen rich) conditions. Most aubrites are heavily brecciated, indicating a violent history for their parent body. Due to an aubrite’s typical light-colored fusion crusts, mostly cream white interiors, and fragile composition, they can be difficult to find in the hot deserts, but more easily found in the blue-ice fields of Antarctica. For these reasons, many aubrites are witnessed falls with the largest being the Norton County meteorite that fell in Kansas in 1948 and with a recovered mass of ~1.1 t. Click to Expand/Collapse
Comparisons of the aubrite spectra to the spectra of asteroids have revealed striking similarities between the aubrites and the main belt asteroid 44 Nysa and other E-class objects. A small near-Earth asteroid, 3103 Eger, the only known E-class near-Earth asteroid (NEA), is suspected of being the actual parent body of the aubrites.
Content above used with permission from J. H. Wittke.