There is more water on the moon that scientists previously thought, and it’s likely hiding in shadowy regions of “eternal darkness.” Space.com reports that two new studies published Monday in Nature Astronomy have expanded our knowledge of water’s existence on the moon, which scientists first detected signs of in 2009. One study, led by Colorado University scientist Paul Hayne, found that 15,444 square miles on the moon have the capacity to hold water, more than double what scientists initially believed. Hayne’s team studied the distribution of cold traps, finding a variety of sizes and permanent shadow areas at both of the moon’s pools. “The temperatures are so low in cold traps that ice would behave like a rock,” Hayne said.“If water gets in there, it’s not going anywhere for a billion years.” A second study led by NASA postdoctoral fellow Casey Honniball found that the spectral signatures researchers picked up were indeed water, not hydroxyl, and is plentiful at high southern latitudes—an important confirmation that validates previous measurements.