EMBLA 2001: The Optical Mission

In August 2001 a new joint collaboration between italian physicists and norwegian engineers was succesfully carried into effect with a new mission to Norway, in order to further investigate a luminous phenomenon which is occurring recurrently in the valley of Hessdalen. The italian research-activity of this year was concentrated in the acquisition of optical data coming from conventional photography, video imaging and video-spectroscopy. Many photographs, videos and some spectra were obtained of the phenomenon. The results coming from the subsequent analysis show that: 1) the luminous phenomenon is a thermal plasma; 2) the light-balls are not single objects but are constituted of many small components which are casually vibrating around a common barycenter; 3) the light-balls are able to eject smaller light-balls; 4) the light-balls change shape all the time; 5) the luminosity increase of the light balls is due to the increase of the radiating area. This mission was able to finally visualize the real structure and nature of the light-phenomenon and its time-behaviour. The cause, and the physical mechanism with which radiation is emitted is currently unknown, and will be investigated in further missions. Some physical hypotheses are amply discussed.