Until recently, planetary scientists thought the Moon was bone dry, with not a drop of water anywhere. They still haven’t found any drops of water, but they have found water molecules spread across much of the Moon. And one of the ingredients for much of that water may come from the unlikeliest of places: the Sun.
When Apollo astronauts brought samples of lunar rock and soil back to Earth, scientists found no trace of water in any of them. But in recent years they’ve analyzed more of the samples with techniques that weren’t around back in the 1960s and ’70s. These studies have revealed water molecules embedded in tiny beads of glass.
At the same time, orbiting spacecraft have detected the chemical “fingerprint” of water mixed with the powdery dirt across much of the lunar surface. And spacecraft have also detected large amounts of water ice at the Moon’s south pole.
The polar water may come from comets that have slammed into craters that never see sunlight. But a recent study says that much of the rest of the water forms when hydrogen in the solar wind rams into the lunar surface. Some of the hydrogen links up with oxygen in the dirt to form water or another compound, known as hydroxyl. So the hot Sun and the dry Moon work together to produce water molecules across the lunar surface.
The Moon is low in the east as darkness falls this evening. The brilliant planet Jupiter stands to its upper right, with the star Aldebaran close to Jupiter.
Script by Damond Benningfield, Copyright 2012
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