Just before Christmas 2011, meteorites were finally discovered from an event which occurred on July 18, 2011 near Tata, Morocco. What makes this particular extraterrestrial bombardment noteworthy is that this was the first shower of Martian meteorites---quite literally, chunks of the planet Mars---known to have occurred in 100 years. (A single Martian meteorite fell in Nigeria fifty years ago.)

How did it get here? Scientists concur an asteroid slammed into the Martian surface which launched bits of Mars into outer space. Why isn't it red? This igneous material is from below the Martian surface. How do we know it's from Mars? The isotopic and mineralogical signatures of Mars are highly specific. Moreover, previous Martian meteorites with glassy impact melt (which this meteorite possesses) have been known at times to contain tiny bubbles...which contain minute volumes of gas...which match perfectly with the signature of the Martian atmosphere.

Approximately 10 kg of material have been recovered from the Tata region. The Macovich Collection acquired more than 2.3 kg of this material to supply collectors, researchers and museums with samples. While there are several dozen intact meteorites weighing between a fraction of an ounce to more than two pounds, the vast majority of specimens are highly fractured---the result of a rough landing on Earth, where they struck a rocky outcropping and shattered on impact.

The pricing below is based on size, esthetics and the percentage of fusion crust (the black veneer a stone meteorite acquires when burning through the atmosphere). While typically less important to researchers (as fusion crust is altered, superheated material), encrusted specimens are prized among collectors

Mars is among the rarest substances on Earth---only a little more than 100 kg are known to exist---and here is a sampling of the most recent arrival: