In the night of Saturday inhabitants of Northern Norway became witnesses of an unusual experiment in the background of the polar lights arose a chain of bright greenish-blue spots, which then disappeared. This effect happened after the launch geophysical rockets in the framework of the NASA project AZURE. Using these missiles at high altitude sprayed particles trimethylaluminum, barium and strontium, which allows scientists to study the behavior of charged particles in the ionosphere where the auroras occur, according to SpaceWeather.com
The experiment AZURE (Auroral Zone Rocket Upwelling Experiment), funded by NASA, involves a series of eight launches of geophysical rockets to a height of 250 kilometres for studying the behaviour of charged particles in the ionosphere, particularly its two layers, E and F. Both of these layers contain free electrons “stripped” from atoms by ionizing radiation of the Sun (this process is called photoionization). By nightfall, when the radiation of the Sun is not providing ionization, electrons and ions begin to “join”. The daily cycle of ionization and recombination makes the behavior of the layers E and F is quite complicated and unpredictable.