Portal:Geophysics/Did you know/2

• ... that sprites (pictured), large but very brief reddish forms of lightning that occur high over thunderstorms, were not photographed until 1989?
• ... that micrometeorites contribute most of the extraterrestrial material that comes to Earth?
• ...that earthquake lights, although described in 373 BC, were not convincingly documented until the 1960s?
• ... that an instrument used to measure magnetic anomalies was originally developed to detect submarines during World War II?