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And, Yes, the Landings Were Real

Image result for moon rocks

Those Apollo moon rocks continue to yield grist for the mill of science.

A new UCLA study re-jiggers estimates of the age of our satellite, increasing her estimated age by 100 million years or so.

When I was in school the dominant theory was that the moon and the earth emerged at the same time. Presumably the one cloud of dust that congealed to become a planet somehow congealed in a bi-modal way to become both planet and satellite.

But recent work has brought another view into prominence.  The earth is at least 4.5 billion years old. The moon is somewhat younger, perhaps about 4 billion years old. When the moon formed, the earth was considerably more solid than a dust cloud, but a good deal more molten than the Earth we know. This premise leads to creative theorizing about how that happened.

The dominant theory at the moment is that the moon formed as the consequence of a collision between the earth and something else, a "planetary embryo" called Theia about 4 billion years ago. The earth itself then was 0.5 billion years old, aka 500 million.

But the latest study pushes back the best-guess age of the moon again, back as I said above 100 million years, toward (but not to) the formation of the earth.

So, if I understand this at all, whether Theia has any real role to play is still in play. The age of the moon when finally settled upon may yet turn out to be the same as the age of the earth, or near enough to leave us back with the bi-modal dust cloud and no collision at all.

What fascinates me about all this is the simple fact that those moon rocks are still in play, shaking up the consensus among scientists and then shaking up the shake-up. A quiet sort of rebuke to the idiots who like to claim the landings never happened.


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