During the devastating September 9, 2017 earthquake off the coast of southern Mexico, residents of Mexico City and Quetzaltenango, Guatemala witnessed mysterious bursts of light in the sky. These lights, however, were not UFOs, exploding transformers, or evidence of a mysterious government conspiracy - instead, they were representatives of an age-old phenomena known as “earthquake lights.”  What could be causing these lights in the sky before, during, and after earthquakes?