(Photo from CETP, text adapted from NASA)
In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights."
During magnetic storms, the glow may move southwards, and on occasion it can be seen in much of the US. It often appears as a glow on the horizon, like the glow preceding sunrise, and has therefore become known among scientists as "aurora borealis" ("aurora" for short), Latin for "northern dawn." A similar phenomenon is also seen in southern polar regions.
Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. The computer screen displaying these words is probably lit up in a similar way, by a beam of fast electrons accelerated electrically towards it, then steered and modulated so as to form letters and pictures.