 the atomic signature often of the water here on Earth. But there's also things like we're now aware that there's huge amounts of water distributed through the Earth's crust. In fact, there seems to be a layer of water that's, I think, about 500 kilometers down in the Earth's crust, which has several times as much water in it as the oceans hold. You know, and it's kind of distributed under very high pressure through all of those rocks down there.