"Space weather scientist Liz MacDonald has seen auroras more than five times in her life, but it was the aurora she didn't see that affected her the most. On the evening of Oct. 24, 2011, MacDonald was sitting in front of her computer at her home in Los Alamos, New Mexico. Forecasts predicted a geomagnetic storm would hit Earth that night and potentially create beautiful aurora. The aurora didn't come to Los Alamos, but MacDonald was still amazed -- not by any bright, dancing lights in the sky, but by the number of aurora-related tweets on her computer screen. People across the eastern United States, from Alabama to Chicago, tweeted about seeing the aurora in real-time. This storm became one of the first wide-scale documentations of aurora activity with social media."