Carl Agee

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ScienceShot: Signs of Water in Martian Meteorite

A meteorite blasted from the surface of Mars contains traces of water, according to a new study. Though the fist-sized rock is relatively dry by earthly standards, it contains between 10 and 30 times the average concentration of water found in other known martian meteorites—and it is the first to closely match certain aspects of the martian crust. A collector purchased the object from a dealer in Morocco in 2011. The meteorite (image; edge of cube is 1 centimeter long), dubbed NWA 7034, weighs almost 320 grams and is a conglomerate of chunks that include bits of volcanic rock. Radioactive dating indicates that the volcanic chunks solidified about 2.1 billion years ago, researchers reveal online today in Science. Overall, the chemical composition of NWA 7034 is strikingly similar to rocks recently analyzed by Mars rovers, and it closely matches the average composition of the Red Planet's crust as estimated by orbiting probes. Samples of the rock contain as much as 6000 parts per million water. The proportions of various oxygen isotopes in the water don't match those found on Earth, a sign that the water likely originated on the Red Planet either as part of the magma fueling the volcano or as ground water that infiltrated or reacted with the molten material after it cooled. NWA 7034's water-rich composition, the researchers contend, bolsters the notion that Mars may have long ago boasted a much warmer and wetter surface than it has today.

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