Red Rock Canyon draws climbers from around the world, offering towering sandstone cliffs just minutes from the Las Vegas Strip. However, after rainfall, those iconic red walls can be more dangerous than they appear — even when the rock looks dry. According to Zach Perzan, an assistant professor of geology at the University of Nevada, Las Vegas, the sandstone at Red Rock — known as Aztec sandstone — is made up mostly of quartz grains held together by a relatively small amount of natural cement.

Rising temperatures, diminished rainfall and steadily increasing usage have taken a serious toll on the Colorado River and the water it contains. Some question whether the Las Vegas Valley will have enough water to last into the future.

When someone talks about frozen water, they typically mean the ice cubes in a cold drink or the vast glaciers in Earth’s coldest corners. What most people don’t know, however, is that H2O molecules can arrange themselves into many different types, or phases, of ice with various structures. Researchers have discovered more than 20 of these phases, the latest of which—called Ice XXI—a team recently created under extreme pressure, allowing water to turn to ice at room temperature.