Space.com - 27 May 2010
Cosmic material that has settled on the moon over billions of years could shed light on where a peculiar type of nitrogen in our solar system came from, a new study suggests.
The powdery lunar surface contains isotopes of nitrogen that, for the most part, appear to have been carried there by still enigmatic sources. Scientists have long known there are different types of nitrogen on the moon, but how it all got there is unknown.
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Although the sun's solar wind has deposited nitrogen on the moon, this solar nitrogen mostly consists of lighter isotopes, as NASA's Genesis spacecraft revealed in samples it collected of the solar wind. In contrast, a much heavier combination of nitrogen isotopes outnumbers this solar nitrogen roughly 10 to one on the moon.
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Solving the mystery behind where this "non-solar" nitrogen comes from could shed light on the ancient forces that drove the origins and evolution of Earth and the rest of the solar system.