A new study published today provides a great example of how science works – as a process of discovery that blends inquiry, theory and argument.
For decades, it has been accepted wisdom that the Moon must be incredibly dry. Not just at the surface but also in the interior, where an ocean’s worth of water can be hidden as traces of water inside minerals.
This idea of a dry Moon fits with the well-established theory that the Moon formed when a Mars-sized planet smashed into the ancient Earth, early in the history of the Solar System. The energy of that collision would have driven off all but the faintest traces of water, even from the minerals that make up Moon rocks.
But now researchers report evidence of surprisingly large amounts of water in rocks formed from ancient volcanic eruptions on the Moon! Based on these new data, large parts of the interior of the Moon may be as “wet” as the interior of the Earth.
This surprising result clashes with what we thought we knew about the Moon. How will the conflict be resolved? Are the new measurements wrong? Is the “giant impact” theory all wet? Can the theory be modified to account for the data? We don’t know. But some researchers won’t rest until the puzzle is solved. The debate should be fun to watch. That’s how science really works.