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NASA
page about NWA2737 here
This group is named for its only member, Chassigny, a meteorite that fell
in France in 1815. As a witnessed fall that was recovered in the early days of
meteoritics, it was one of the first meteorites to be recognized as a genuine
rock from space, and it subsequently proved to be one of the most intriguing
ones. Chassigny is a cumulate rock, resembling a terrestrial dunite. It
consists of about 91% iron-rich olivine, 5% clinopyroxene, 1.7% plagioclase,
1.4% chromite, 0.3% melt inclusions, and other accessory minerals and phases.
The melt inclusions contain rare amphiboles, and cracks within Chassigny are
filled with carbonate and sulfate salts, indicating a mild pre-terrestrial
aqueous alteration.
In
1999, we brought a black rock from Morocco, broken in several
pieces. This rock was not immediately recognized as a meteorite, so we
filed it with hundreds of other "meteorwrongs". It was only in
2005
that a fragment was entrusted to scientists and that the true nature of
the sample was recognized. Called "Diderot" by the
scientists in homage
to the 18th century encyclopedist of Langres in France, this meteorite
bears today the name of Northwest Africa 2737 (NWA 2737), according to the
international nomenclature.
Although the surface of Mars is studied today by the
NASA rovers Spirit
and Opportunity, these meteorites are the only samples of the red
planet ever available for researchers. Indeed, the program of Martians
sample return being quasi-abandoned, these discoveries bring priceless
harvests of data to understand the evolution of our solar system.
No other Chassignite has ever been discovered since
Chassigny fell in
1815. With the discovery of NWA 2737, a huge lack has been filled.
The total number of our unpaired SNC meteorites is now 8.
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