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Nature’s Neon Lights: Aurora Borealis & Aurora Australis

Beautiful, magical, eerie, surreal, awe-inspiring…

It’s hard to come up with adjectives to adequately capture the sight of the colorful, glowing, shifting curtains of light we know as the Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights). In ancient times, their appearance was both feared and revered. And while we now have the scientific knowledge to explain this natural phenomenon, we are still held captive by its mystical spell. Fortunately we live in a time when technology (via live webcams) can help us feed our endless fascination for nature’s neon lights.

Live webcam at Churchill, Manitoba, Canada (3 hours ahead of west coast US)

What causes Auroras?

From: Aurora | NOAA / NWS Space Weather Prediction Center:

The Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights) are the result of electrons colliding with the upper reaches of Earth’s atmosphere… The electrons are energized through acceleration processes in the downwind tail (night side) of the magnetosphere and at lower altitudes along auroral field lines. The accelerated electrons follow the magnetic field of Earth down to the Polar Regions where they collide with oxygen and nitrogen atoms and molecules in Earth’s upper atmosphere. In these collisions, the electrons transfer their energy to the atmosphere thus exciting the atoms and molecules to higher energy states. When they relax back down to lower energy states, they release their energy in the form of light…

Earth’s magnetic field guides the electrons such that the aurora forms two ovals approximately centered at the magnetic poles… Often the auroral forms are made of many tall rays that look much like a curtain made of folds of cloth. During the evening, these rays can form arcs that stretch from horizon to horizon. Late in the evening, near midnight, the arcs often begin to twist and sway, just as if a wind were blowing on the curtains of light. At some point, the arcs may expand to fill the whole sky, moving rapidly and becoming very bright. This is the peak of what is called an auroral substorm. Then in the early morning the auroral forms can take on a more cloud-like appearance. These diffuse patches often blink on and off repeatedly for hours, then they disappear as the sun rises in the east.

What causes the different shapes and colors of auroras?

From  What’s The Aurora Borealis And Where Can You See It? – WorldAtlas:

Aurora Borealis lighting displays may take the form of patches, shooting rays, arcs, diffused clouds, or streams of multi-coloured light. The colors can range from shades of blue, yellow, violet, red, and to the more commonly occurring pale pink and green. The different colors occur depending on which particular types of gaseous particles are present in the atmosphere. For example, a pale yellowish-green hue appears due to the presence of oxygen molecules some sixty miles above the Earth. Conversely, all-red auroras, which are rarer to see, are created because of oxygen located at heights of up to two hundred miles. Blue or shades of purple are due to the atmospheric presence of nitrogen.

When and where to view?

More live webcams of Aurora Borealis:

(Viewing is affected by local weather conditions and differing time zones at webcam locations.)

Time-lapse videos of nature’s neon lights:

A video explainer:

What Causes Auroras? – YouTube

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