The Northern Lights are poetry, they are nature's light show and they are quantum leaps in the oxygen atom. They are elementary particle physics, superstition, mythology and fairy tales. The Northern Lights have filled people with wonder and inspired artists; they have scared people into believing that the end is near. It was not possible to provide more exact explanations of the phenomenon until modern particle physics was developed, and knowledge of the details of the Earth's magnetosphere was based on satellite measurements. When the Northern Lights are seen over Tromsø, it occurs according to a set pattern, although this pattern varies considerably. The explosion begins with a phosphorescent glow above the northwest horizon. The glow goes out and returns, and then an arc lights up. It rises into the sky. And new arcs light up and follow the first. Small waves and curls move along the arches. Then within a few minutes you see a dramatic change in the sky. A hailstorm of particles hits the upper atmosphere in what is called an aurora substorm. Rays of light shoot down from space, forming drapes that spread across the sky. And they really remind us of draperies or curtains, which flicker in the wind. And you can see a purple and red trim at the bottom and top ends. Or the colors are all mixed together, intertwined into each other. The curtains disappear and are reconstituted thanks to new rays of light coming down from the space. Above our heads we can see the rays coming out in all directions forming what is called the corona of the aurora. After 10-20 minutes the storm ends and the activity decreases. The bands widen, disintegrating into a diffused light across the entire sky. We can't see individual pockets of light, but the overall effect is bright enough for us to make out details of the countryside around us. If we look very carefully, we can see the remnants of the Northern Lights show up as faint, pulsating flames. Clouds of light that turn on and off regularly every 5 - 10 seconds as if from an electric switch. Nature's giant light show is over. What causes the Northern Lights? To answer this question, let's start with the sun, whose energy production is far from uniform and fluctuates on an 11-year cycle. Maximum production coincides with high sunspot activity when processes on the sun's surface throw out particles... half the paper. .....all in the sky.7) Bands of Northern Lights on top of each other, rising towards the zenith indicate the secondary storm is starting.8) Rays of light shot down from space indicate higher activity. 9) Curtains are formed by waves at the lower end.10) Curls and waves sway along the curtains.11) The curtains appear to tremble in the wind. Nearby maximum activities.12) The interaction between moving charged particles and the Earth's magnetic field creates a charged magnetic field. Particles descend along magnetic field lines.13) Rays and drapes can go out in one place in the sky and form in another. 14) During the peak of a secondary storm, the entire sky may be filled with light.15) An all-sky (fish eye) image showing that the drapes are stretched from east to west, across the zenith.16 ) When the activity reaches Zenith, by an optical illusion, the rays appear to extend in all directions above our heads. This form of aurora borealis is called corona aurora. Works Cited http://www.uit.no/npt/nordlyset/nordlysbilder.en.html http://www.uit.no/npt/nordlyset/Way North Magazine, Tromsø Museum publication.