The moon may be much younger than previously believedDecember 20th, 2007 - 1:28 pm ICT by admin
Washington, Dec 20 (ANI): New tests of moon rocks show that the moon was formed after an Earth-Asteroid collision later than previously believed, which indicates that the moon is much younger than earlier thought.
Prior studies had found that the moon formed when Earth was about 30 million years old. But now it appears that the impact occurred 30 million years after that.
“And it could have been as late as 140 million years after the solar system began to condense,” said Alan Brandon of NASA Johnson Space Center in Houston, Texas.
According to a report in National Geographic News, the key to the new study was a new method for looking at trace isotopes in moon rocks, particularly of the element tungsten-182.
Tungsten-182 is formed by the radioactive decay of halfnium-182, which has a half-life of nine million years.
By comparing the abundance of tungsten-182 to that of another isotope, tungsten-184which is not formed from halfniumit’s possible to determine how old rocks were when the magma that formed them solidified.
“This nice thing is that, this radio-isotopic clock is very short-lived,” said Brandon. That makes it extremely useful for dating events early in the life of the solar system, he added.
Another finding that has emerged from the tests is that the moon’s early ocean doesn’t appear to have solidified until about 120 million years after the beginning of the solar system. That’s 60 million years after the most likely date for the creation of the moon.
“That means that the moon stayed molten for quite a while,” said Brandon. (ANI)
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