Apart from the fact that there's water on the moon, the data will help us find out where the water is. NASA's lunar prospector showed us some subtle data aspects, like indicating that the top surface of the poles, anywhere from 4 to 40 inches of the soil, is water depleted. So we may need the microwaves to penetrate 40 inches into the soil. More data could help us find out exactly how deep the water is. Also, what's its concentration? Some estimates indicate that water may form 1-2 percent of the soil. But others say it's as high as 40 percent, in which case the water would fill up all the interstices of the soil. This would make mining it very tough, since the soil would be as hard as granite at the temperatures found on the moon. Microwaves would have many advantages: they're simple, and we can heat the water in situ to extract it.