The new Dune movie looks pretty cool, but it's hard to beat plain old sand dunes. The ever-changing landform is comprised of tiny particles of all sorts of things—quartz, gypsum, coral, even war shrapnel! The term "sand" refers to particle size, not constitution, so "sand" can be made up of almost anything. As a result of Aeolian processes, sand particles form ordered ripple and wave patterns that are just a few centimeters high, and they also form gigantic sand dunes which you can climb, photograph, and surf.
- Sand dunes submerged a town. Beneath dunes along the coast of Lake Michigan lies the remains of Singapore, Michigan, a town that began in the 1830s. It had its own currency of "Singapore dollars" (back when small banks could just make a currency!). After fires ravaged Chicago and other cities of the upper midwest, Singapore's logging industry exploded, and the town's tree cover slowly disappeared. Without the forests, the coastal winds blew sand into the town, and it was evacuated by 1875. More on Wikipedia. As ongoing desertification turns more areas into deserts, sand threatens communities like Fowler's Bay in Australia.
- Sandboarding: just dune it! Adventure seekers ride boards down sand dunes in an extreme sport that may have originated in ancient Egypt. You can't build a lift on a dune, so to get back up to the top, you hop in a dune buggy.
- Dunes were almost the classic computer background. Charles O'Rear, the photographer who snapped the famous Bliss image used as the default background for Windows XP, also submitted a photo called "Full Moon over Red Dunes." It was the original wallpaper until users complained that it vaguely resembles buttocks. Microsoft subsequently opted for grassy scene we know and love.
- Dunes are out of this world! If sand dunes seem otherworldly, it's because they are. NASA uses sand dunes in Colorado to test its rovers because the landscape is similar to parts of Mars. On Saturn's moon Titan, 100-meter-tall dunes of hydrocarbons may be the result of cosmic rays hitting ice. On Pluto, weird dune fields (which National Geographic compares to "an alien thumbprint pressed into extraterrestrial ice") are made of methane. There are dunes on Mars too, and NASA found an area with sand dunes in the shape of dots and dashes. They call it "Martian Morse Code."
- Dunes sing, sort of. When sand blows in the wind, the particles' vibrations give rise to haunting symphonies. Wet sand can also produce a quacking nose when you shuffle your feet on it. The process is not well understood.