A PARTIAL SLICE OF THE MARTIAN METEORITE NWA 8716 (“JRIFIYA”)

A PARTIAL SLICE OF THE MARTIAN METEORITE NWA 8716 (“JRIFIYA”)

Mars — SNC Shergottite

The Sahara Desert, Morocco

66 x 55 x 1.5mm (2.5 x 2 x 0.1 in.) and 21.75 g

The determination of the Martian origin of this specimen is the result of research by scientists throughout the world. In addition to the more arcane chemical markers, most Martian meteorites — such as the current example — exhibit an unusually young crystalline age (indicating that they cannot be from asteroids, which cooled about 4½ billion years ago). Many Martian meteorites also contain water-bearing minerals, consistent with the evidence for water on Mars. The smoking gun of Martian origin of material similar to this partial slice appeared in 1995 when minute amounts of gas found in tiny glassy inclusions of two suspected Martian meteorites was analyzed — glassy inclusions that are largely identical to what is seen in this cut partial slice — and the gas was found to match perfectly with the signature of the Martian atmosphere as reported by NASA’s Viking missions. As is the case with lunar meteorites, the delivery mechanism is an asteroid impact that jettisoned material off the Martian surface into an Earth-crossing orbit. The impact that blasted NWA 8716 off the Martian surface would have required such massive force that would transform the rock’s plagioclase grains into glass — the glass inclusions now seen. This specimen also contains olivine microphenocrysts in a groundmass of pyroxene, chromite and troilite. Featuring a signature mottled-green matrix, Jrifiya is among the most beautiful Martian samples known.

LITERATURE

The official classification of this Martian meteorite appears in the 104th edition of the Meteoritical Bulletin. A copy of the abstract accompanies this offering.