The leading idea for the birth of the Moon says it formed as the result of a giant impact between the newborn Earth and another planet-sized body. In part, that picture is based on analysis of lunar rocks and soil brought to Earth by the Apollo astronauts — the composition of the Moon closely matches that of Earth’s outer layers.
But a study published earlier this year seems to contradict that scenario. It suggests that Earth was a single parent — that somehow it gave birth to the Moon without the help of a second planet.
That study, too, was based on analysis of the Apollo samples. But the analysis was carried out in just the last few years, with tools that didn’t even exist when the Apollo missions were flown.
After Apollo, NASA set aside quite a bit of the samples for future study. The pace of scientific development made it certain that new tools in the decades ahead would provide new answers to many of the questions about the Moon.
And that’s just what’s happened. New electron microscopes see far greater detail than those of the 1960s and ’70s. And other tools make it possible to detect smaller levels of various materials in the samples.
A study in the last couple of years, for example, discovered water in beads of volcanic glass — far more water than anyone had expected to find on the Moon. It’s just one of the secrets that are being revealed by new looks at old moonrocks.
Tomorrow: weathering a busy season of space weather.
Script by Damond Benningfield, Copyright 2012
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