Two decades of spacecraft images reveal more than 1,000 dust devils whipping across Mars at unexpected speeds, offering fresh insight into how wind and dust shape the Red Planet.
The Big Bang essentially created two elements: hydrogen and helium. It also produced tiny traces of lithium and a few other light isotopes, but in the beginning there was hydrogen and helium. All the other, heavier elements formed later, either in the cores of stars, through stellar collisions, or other astrophysical processes. Even now hydrogen and helium make up so much of the material world that astronomers refer to all other elements as metals. Dust in the wind, you might say.
