"Knocking stones" on Mars

Scientists uncover meteorite finds

Mars meteorite found on Mars with a diameter of approximately 30 centimeters from the Mars Rover Opportunity © NASA / JPL
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For two years ESA and NASA's space missions have been exploring our neighbor's planets and discovering new secrets. For example, a few months ago, the discovery of an enigmatic rock chip on Mars caused a stir and only recently did a look through the dusty surface of the Red Planet possible with the aid of state-of-the-art equipment. Above all, scientists from the USA but also from Germany are involved in the decoding of these stony puzzles.

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"I never thought we would use our instruments on rocks that came from elsewhere than Mars, " says Steve Squyres of Cornell University in New York, explaining his surprise when the Mars Rover Opportunity dropped to a mere 30 centimeters a few months ago big pieces of rock collided. This differed from all previous finds and showed no similarity to known Martian rocks. Already the first investigations on the basketball-sized and lumped lumps pointed to an unusually high metallic concentration - maybe a meteorite?

Mineralogical search for traces

The scientists then interrupted the planned route of the rover and steered him closer to the find. Using the so-called Mössbauer and Alpha Particle X-ray Spectrometers (APXS), two devices developed and built in Germany, they made accurate measurements of rock aggregate composition over the following days. In addition to NASA experts, German scientists such as Jutta Zipfel from the Department of Cosmochemistry at the Max Planck Institute for Chemistry in Mainz were also involved.

After just a few days, the mineralogical-chemical analysis left no doubt: Opportunity had found the rest of a minor planet. For what looked like a piece of rock was actually a piece of metal made of an iron-nickel alloy - an iron meteorite from another planet. The Mainz-developed APXS device on board Opportunity was even able to determine the concentration of the trace element germanium. With their help, the scientists could even unambiguously assign the metal-containing fragment to a group of iron meteorites, which is also known from earthly finds. "Just think of where such an iron meteorite came from: a ruined planet or planetsimal big enough to form a metallic core and a rocky mantle, " Squyres explains the meaning of the find. display

Mars meteorites on earth

Since this spectacular event, there have been many other surprising discoveries on Mars, such as evidence of plate tectonic movements or a mysterious water ice crater at the North Pole. For Jutta Zipfel, too, Mars has long since lost none of its fascination after the release of the iron meteorite. The geologist currently heads the meteorite research section at the Senckenberg Research Institute. In addition to numerous meteorites of unknown origin, she also looks after "old acquaintances" in the truest sense of the word: Mars meteorites.

Mars meteorite ALH 84001 NASA

In contrast to the iron meteorite, these findings actually consist of mars rock. Because when an asteroid or a larger celestial body falls on Mars, the impact of the impact can cause the body of the planet to be ejected into space. On their journey through space, some of them hit the earth once before. The few clumps of rock that do not evaporate in the atmosphere but reach the earth's surface are considered by scientists to be true treasures. Not only because of the estimated 30, 000 meteorite finds worldwide only about 35 rocks are also proven to come from Mars, but because they reveal as the only direct source also more about the structure and composition of the Martian surface.

(NASA, Section Meteorite Research at the Research Institute Senckenberg, 23.12.2005 - AHE)