Shergottites

Shergottites are a group of stony meteorites that belong to the broader category of Martian meteorites, also known as SNCs (after the type localities Shergotty, Nakhla, and Chassigny). These meteorites are believed to originate from Mars based on their mineralogical composition, isotopic ratios, and trapped gases that match the Martian atmosphere. Shergottites are among the youngest known Martian rocks, with crystallization ages ranging from approximately 180 to 300 million years ago, which is relatively recent compared to the age of the solar system.

The name "shergottite" is derived from the Shergotty meteorite, which fell in India in 1865. This group is characterized by their fine-grained, basaltic texture and high concentrations of pyroxene, an iron- and magnesium-rich silicate mineral. Shergottites often contain shock features, indicating they experienced significant impacts on Mars before being ejected into space. Some members of this group also exhibit signs of alteration due to interaction with water, suggesting past aqueous activity on Mars.

Shergottites are further divided into several subtypes based on their mineralogy and texture, including lherzolitic, olivine-phyric, and pigeonite-phyric varieties. Their study provides valuable insights into the geological history of Mars, including volcanic activity, crustal formation, and potential past habitability. These meteorites are particularly important for planetary scientists because they offer direct samples of Martian rocks that can be analyzed in terrestrial laboratories, complementing data obtained from orbiters and rovers.

The recovery of shergottites has occurred through both witnessed falls and finds, with notable examples including EETA79001 (Elephant Moraine, Antarctica), Zagami (Nigeria), and Los Angeles (United States). Their rarity and scientific significance make them highly sought-after specimens in meteorite collections worldwide.