Chassigny, Martian meteorite in Chassigny, France

Chassigny is a Martian meteorite that fell in 1815 near the village of the same name in northeastern France and gave its name to a whole class of similar rocks called chassignites. It is made mostly of olivine, with smaller amounts of pyroxene, feldspar, and oxide minerals arranged in a crystalline structure.

Chassigny fell on October 3, 1815, at about 8:00 am in the commune of Chassigny, Haute-Marne, north-eastern France. It was the first of the three original SNC meteorites, before Shergotty and Nakhla. Long suspected to be a rock ejected from Mars, this origin was confirmed by measurements made in situ by Martian probes. It remained the only known chassignite until NWA 2737 was found in the Moroccan Sahara in 2005.

The word "chassignite" now names an entire group of Martian rocks, all named after the small French village where this meteorite landed. Anyone who sees one of these specimens in a museum is looking at a rock that gave its name to a whole scientific category.

Fragments of the meteorite are held in several museums and scientific collections in France and abroad, where they are displayed in exhibitions on planetary science. A visit to a natural history museum or a science center with a focus on astronomy gives the best chance to see a specimen up close.

Chassigny was the only known chassignite until NWA 2737 was found in the Moroccan Sahara in 2005. A third, NWA 8694, described in 2020, has a mesostasis similar to some nakhlites, suggesting a link between the two types of Martian meteorites.