Scientists say that they have found proof of water on the moon—by looking in the desert in northwest Africa.

A mineral that requires the presence of water to form was discovered in a lunar meteorite by a team of Japanese scientists.

They identified the mineral moganite in just one of 13 lunar meteorites, which they say proves that the mineral wasn’t created by some process after it had landed on earth.

“This is significant because moganite is a mineral that requires water to form, reinforcing the belief that water exists on the Moon,” reads a statement on June 13 from Tohoku University, where the research was carried out.

“For the first time, we can prove that there is water ice in the lunar material,” Masahiro Kayama, lead researcher with the Kayama told Space.com. “In a moganite, there is less water, because moganite forms from the evaporation of water.”

“Many people think that remote-sensing spacecraft only found the evidence of water around the poles simply because we can’t see under the surface below a few millimeters,” Kayama said. “This is the first insight into water in the subsurface zone.”