Accelerate progress in our three core enterprises — Explore Worlds, Find Life, and Defend Earth. You can support the entire fund, or designate a core enterprise of your choice.
Crossbeds at Walnut Canyon Crossbeds at Walnut Canyon are essentially fossilized sand dunes from when Arizona was a coastal desert. The direction that the layers are tilted tells us that the prevailing winds blew from north to south, although the various sets of layers in this image actually reflect several wind directions. Ryan Anderson