Constant eruptions on our sun eject highly charged ‘winds’ in all directions into space called the solar wind stream at over 1,000,000 miles per hour. When directed towards earth, the solar wind is drawn into our magnetic field causing a high altitude electrical discharge process with ionospheric gases and emit the light we see as aurora.
Q & A's
‘AurorA – Alaska’s Great Northern Lights’ is not a “documentary” about the science of aurora. But rather ‘AurorA’ is an evolving work-of-art to show people worldwide what a remarkable natural event the aurora is across the grand night skies of Alaska. With recent leaps in HD technology, ‘AurorA’ is now projected in High Definition Blu-Ray® quality. Dave has included in the show a portion of science about aurora as an introduction but the rest of the show has stunning images played to a wonderful music score. This is the result of a desire to capture the absolute best auroral displays Alaska has to offer. Having chased aurora across Alaska since early autumn of 1980, Dave found it to be the most difficult subject matter and task to be devoted to. There are countless hours in the field, the need for unending patience, more lost sleep than one can even begin to imagine and my ‘office’ is extremely cold most of the time.For those of you wishing to immerse yourself in copious amounts of auroral sciences please visit: http://www.gi.alaska.edu.The Geophysical Institute in Fairbanks is the largest central database for in-depth studies of aurora in the world. There are no ‘quick’ answers to questions about aurora. It still remains one of the earth’s great-unsolved mysteries. For every answer, there are many more questions. All science aside, bundle yourself up some night, lose some sleep, go out, be safe, and enjoy the greatest light show on Earth.
What creates Aurora?
What causes the colors of Aurora?
Electrons carried along with the solar wind strike atoms of nitrogen and oxygen. Atomic oxygen creates the green aurora, nitrogen emits pink-red, blue and purple aurora, while the rare bright red and orange-red aurora are produced from higher altitude atomic oxygen.
The energy output of the solar wind traveling along the earth’s magnetic field lines creates the patterns of aurora we see. These include homogenous arcs, bands, active arcs, rays, pillars, draperies or curtains and coronas.
What creates the shapes of Aurora?
The aurora exists constantly as oval shapes over both Polar Regions of our earth as well as other planets in our solar system. The Aurora Borealis, or ‘Northern Lights’, is viewed far more frequently than the Aurora Australis, the ‘Southern Lights’ because there are huge land masses in our northern hemisphere and mostly water around Antarctica. The auroral ovals are basically ‘born’ around the Arctic and Antarctic Circles. As the aurora becomes more energetic, the ovals expand and can be seen in the night skies closer to areas above and below the equator.
Where can Aurora be viewed?
No! The temperature on earth has absolutely nothing to do with auroral activity or formation. From the edge of space and beyond it is well below freezing all the time.
Aren’t Auroras better the colder it gets?
No! To view the aurora, one needs darkness/night/twilight. Alaskan summers do not allow a view into the heavens because the atmosphere is too lit by the sun. Southern Canada and the northern tier states are able to see auroras in the summer because ‘nighttime’ still exists. Late July through early April is the best window to view aurora in Alaska.
Can Auroras be seen during Alaska’s summers?
Auroras are called ‘geomagnetic storms’. Powerful storms can cause great havoc by creating immense surges on power grids, transmission lines, navigation systems, and radio communications and at satellite altitudes. Space Shuttle Astronauts must seek the protection inside the shuttle itself when auroras are present due to higher levels of radiation in space.
How do Auroras affect our Earth?
No! While numerous people have stated they’ve “seen the aurora touch the ground” it has never been scientifically proven to be able to occur that low. The ‘recipe’ for auroral formation cannot exist below a certain height, usually just below 60 miles above our heads. Auroras normally extend from 60 miles at the lower border to 200 miles high. Very powerful auroras have been measured as high as 600 miles. It is an optical illusion that auroras touch the ground because this massive phenomenon bends and vanishes over the curvature of the earth and appears to lower as we lose sight of it.
Do Auroras ever touch the ground?
Sometimes! Consider the ‘success rate’ of your local weatherperson. When trying to predict auroras the degree of difficulty increases a thousand fold. Science and technology are bringing us closer to the day when such predictions will be far more accurate.
Can Auroras be predicted?
Mostly it takes the ‘patience of a glacier’ with some cold fingers and toes. If you have a good 35mm SLR camera (not a ‘point & shoot’), a cable release and a tripod, you’re almost ready to go. Pick out a variety of slow to mid-range ASA films you enjoy working with and pick out a nice dark location. Play around with your exposures because the aurora evolves in seconds. If you prefer to try to capture the aurora digitally then your learning curve will be quite steep. Digital photography is breaking new ground every year & all digital cameras are not created equal. The high-end more expensive Digital SLR’s do offer the best possibilities.