Monday, June 20, 2005

Those Crazy Asteroids

Magma Oceans Covered Early Asteroids
During their formation, many planetary bodies in our solar system melted significantly, allowing denser materials to sink to their centers in a process known as differentiation. But how widespread this process was when it came to another class of early solar system body, asteroids, remains unclear. New findings published in the latest issue of the journal Nature suggest that for at least two of our solar system's major asteroids, melting was dramatic.

In the magma oceans, other elements in the asteroids would have separated out according to mass, the researchers report. The resulting layered composition of such an asteroid could have contributed to the uneven distribution of elements among the planets, they say, if developing protoplanets crashed into the asteroid once it had cooled. In this scenario, the elements abundant in the crust would be transferred to one planet and those present in its core would end up on another. According to the report, Earth's high magnesium to silicon ratio is one anomalous feature that could be explained under these circumstances.

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