Ratio of hydrogen to deuterium suggests a common source
Water trapped deep within the moon’s interior came from the same source as water on Earth, a new study reveals. The research suggests that the moon seized a healthy supply of water from Earth when the satellite formed in the aftermath of a cataclysmic collision 4.5 billion years ago.
“This is an important result and a surprising result,” says David Stevenson, a planetary scientist at Caltech.
The findings come from the laboratory of Brown University geochemist Alberto Saal, who has spent the last five years trying to overturn the conventional wisdom that the moon was born dry. In the new study, published May 9 in Science, Saal and his team analyzed the water in two moon rocks returned by Apollo astronauts in the 1970s. The rocks probably formed from buried magma that was forced to the surface during volcanic eruptions early in the moon’s lifetime. They contain small globules of hardened lava embedded within crystals that prevented th