* Astronomy

NASA Scientists Find Dynamo at Lunar Core May Have Formed Magnetic Field

The moon no longer has a magnetic field, but NASA scientists are publishing new research that shows heat from crystallization of the lunar core may have driven its now-defunct magnetic field some 3 billion years ago.
Magnetized lunar rocks returned to Earth during the Apollo missions established that the moon once had a magnetic field. The moon's magnetic field lasted for more than a billion years and, at one point, it was as strong as the one generated by modern Earth. Scientists believe that a lunar dynamo -- a molten, churning core at the center of the moon -- may have powered the magnetic field, but previously did not understand how it had been generated and maintained.
In a paper recently published in Earth and Planetary Science Letters, scientists in the Astromaterials Research and Exploration Science (ARES) Division at NASA's Johnson Space Center in Houston argue that this dynamo was caused by crystallization of the lunar core.
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