The Grand Canyon can hold about 5.45 trillion cubic feet. Very rarely, it fills up with fog. Here's what it looks like, and why this happens, in 60 seconds. Subscribe to our channel! http://www.youtube.com/subscription_center?add_user=voxdotcom Vox.com is news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com to get up to speed on everything from Kurdistan to the Kim Kardashian app. Check out our full video catalog: youtube.com/voxdotcom/videos Follow Vox on Twitter: https://twitter.com/voxdotcom Or on Facebook: https://www.facebook.com/Vox