ABSTRACT
Lightning flashes through the sky millions of times a day, and humans have witnessed the spectacle repeatedly for tens of thousands of years. It was probably the spark for organic life, an idea tested in the lab back in 1952 when the chemist Harold Urey and his graduate student Stanley Miller exposed a simulation of the early atmosphere to artificial lightning. The widespread electrical phenomenon of lightning has existed for much of the Earth’s lifetime, but its origin story remains a mystery to this day. Physicists learned to dissect the development of a bolt with high-speed cameras. Researchers went on to trigger lightning artificially by sending rockets trailing copper wire into thunderstorms. Martian lightning is intriguing because the planet is a potential site for past if not present alien life. Starting in 2008, NASA landers have found perchlorates, compounds containing the negative ion ClO4, in Martian soil.
