William Atkins
Sunday, 18 January 2009 22:22
Science -
Space
Page 1 of 4
MIT astronomers have discovered that a lunar liquid core, which existed about 4.2 billion years ago, generated the Moon’s current magnetic field. Concerning why we should go back to the Moon, one of the MIT scientists said we have literally "only scratched the surface."
The Moon’s external magnetic field is about one-hundredth the size found on the Earth. However, it does not have a dipolar magnetic field, like the Earth, which is a magnetic field that is generated by a rotating metal-based core.
Such a geodynamo—as scientists call a magnetic field generated by the geological interior of a celestial body—is today absent from the Moon. The only magnetization that exists on the Moon comes from its crust.
But, how does it occur?
The answer is that scientists did not know the source of the small magnetic field found on the Moon.
The MIT researchers added within the abstract to their paper,
“It is uncertain whether the Moon ever formed a metallic core or generated a core dynamo. The lunar crust and returned samples are magnetized, but the source of this magnetization could be meteoroid impacts rather than a dynamo.”
However, now these scientists at the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, U.S.A., think they have uncovered the secret of the Moon’s magnetic field.
These MIT scientists studied one rock brought back from the Moon by U.S. astronaut Harrison "Jack" Schmitt, who walked on the Moon as part of the
Apollo 17 mission (December 7-19, 1972), which also included Gene Cernan (commander, and fellow moonwalker) and Ron Evans (command module pilot).
A U.S. geologist at the time he walked on the Moon, Schmitt Apollo 17 lunar module pilot) was the only scientist to participate in moonwalks.
Page two discusses this very special piece of lunar rock.
