LIGHTNING: DOES IT GO DOWN OR UP?

摘要

Earth is one of four planets in our solar system-along with Venus, Jupiter, and Saturn-that experiences giant atmospheric electrical discharges, or lightning. Only on our planet, however, are there sentient creatures pondering the origin and nature of these atmospheric pyrotechnics. This is most appropriate, given that the energy of ancient lightning flashes might have produced some key amino acids comprising the organic molecules that allowed for the evolution of these curious Homo sapiens.