There is a longstanding question.

• Position: SCIENCE SCENE - Earth science - Brief article

There is a longstanding question that recently has moved to the forefront of earth science: did our planet make its own water through geologic processes, or did water come to us via icy comets from the far reaches of the solar system? The answer is likely "both," according to earth scientists Wendy Panero and Jeff Pigott, who presented their findings at a recent American Geophysical Union meeting. Moreover, the same amount of water that currently fills the...