SNC meteorites

SNC meteorites

A small group of stony (achondrite) meteorites, named after its three main members Shergotty, Nakhla, and Chassigny. These igneous rocks seem to be only 1300 to 200 million years old. It is suggested that they have been ejected from Mars by some crater-producing event.
Mentioned in ?
References in periodicals archive ?
Although NWA 7034 has similarities to the SNC meteorites, including the presence of macromolecular organic carbon, this new meteorite has many unique characteristics.
The SNC meteorites, the letters standing for the names of the three most prominent of the group (Shergotty, Nakhla, and Chassigny), were unlike almost any other.
Gerlind Dreibus and Heinrich Wanke of the Max Planck Institute for Chemistry in Germany estimated the chemical composition of the Martian mantle, the deep region that partially melted to produce the magmas from which SNC meteorites crystallized.
The value inferred from melt inclusions in SNC meteorites (less than 200 meters, perhaps appreciably less) might be low because it is based on only a portion of the total volume of igneous rocks.
In summary, SNC meteorites do not provide a unique answer to the question of how much water has been outgassed on Mars, but they do give new information complementing that obtained from other observations and measurements.
But the SNC meteorites also suggest that liquid water must exist underground.
In fact, report O'Keefe and Ahrens, "oblique impact-induced jet plume entrainment appears to be the only mechanism that provides the physical mechanism required to explain the acceleration to high speed of lightly shocked planetary samples such as SNC meteorites."
Third, highly oxidized (ferric) iron, the primary component of rust, occurs within some minerals in SNC meteorites; this is the same component responsible for the red color of Martian soil.
If the SNC meteorites truly come from Mars, what have we learned about the planet?