Artificial aurora lights-up arctic skies

coondoggie writes: "It did not light up the sky like real aurora borealis can but researchers with the U.S. Naval Research Laboratory said they have created an artificial version that can be used to explore ionospheric occurrences and their impact on communications, navigation and space weather. Specifically what the researchers did was produce what they called a "sustained high density plasma cloud in Earth's upper atmosphere," using the 3.6-megawatt High-frequency Active Auroral Research Program (HAARP) transmitter facility, Gakona, Alaska."