Complete Slice Of Rock From Mars — NWA 7397

Specimens of the planet Mars are among the rarest substances on Earth, with slightly more than 600 pounds (275 kilograms) known to exist. These samples arrived on Earth as a result of a massive asteroid impact on the Martian surface which ejected chunks of material into interplanetary space. A portion of this material gravitationally perturbed into an Earth-crossing orbit. Numerous chemical and isotopic markers suggested a Martian genesis for an unusual group of meteorites, and in 1995 a landmark study provided the smoking gun: two suspected Martian meteorites evidenced tiny voids, and within these voids were tiny volumes of gas — which perfectly matched the signature of the Martian atmosphere as determined by NASA’s Viking Missions.

This complete slice of NWA 7397 (the 7397^th meteorite to be classified following its recovery in what scientists designated as the Northwest African corridor in the Sahara Desert) was cut from the main mass. The determination of Martian origin was conducted by a team of scientists led by Dr. Anthony Irving, the world's foremost classifier of planetary meteorites, and his analysis which was published in the Meteoritical Bulletin following a peer review by the scientists on the Nomenclature Committee of the Meteoritical Society accompanies this offering.

Found in 2012 by a Berber meteorite hunter, NWA 7397 features salmon-hued pyroxene oikocrysts (crystals that contain smaller crystals of other minerals — in this particular instance, crystals olivine and chromite). NWA 7397 shares the chemical and isotopic fingerprint of other documented Martian meteorites. Maskelynite — the vesicular impact glass present only in meteorites and meteorite impact craters, which is known to contain samples of Martian atmosphere in select Martian meteorites — is much in evidence which makes it reasonable to conclude this specimen contains Martian atmosphere. Among the rarest substances on Earth, this is a select representation of the planet Mars.