The moon - so familiar - actually once swivelled about in a part of space completely alien to our own, where strong magnetic fields shaped the ancient fossil nature to such an extent that faint traces of magnetism remain in some moon samples.
Moon rocks delivered to Earth by Apollo astronauts held a mystery that has plagued scientists since the 1970s: Why were the lunar rocks magnetic?
Now, scientists at MIT think they have a solution. Some 4.2 billion years ago, the moon had a liquid core with a dynamo (like Earth's core today) that produced a strong magnetic field. The moon's magnetic field would have been about 1-50th as strong as Earth's is today, the researchers say.
The rock was collected during the last lunar landing mission, Apollo 17, by Harrison "Jack" Schmitt, the only geologist ever to walk on the moon.
"Many people think that it's the most interesting lunar rock," said MIT's Ben Weiss, who is senior author of a paper on the new finding being published in the Jan. 16 issue of the journal Science.
Rather, the rock readings showed it must have remained in a magnetic environment for a long period of time — millions of years — and thus the field must have come from a long-lasting magnetic dynamo.
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clipped from news.yahoo.com
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