What are the Northern Lights

The Northern Lights also called Polar Lights are bright colored lights that dance across the night sky almost like curtains fluttering in a breeze. In truth, they can be seen in both the northern and southern hemispheres, but in the U.S, mostly in the far northern skies. The scientific name for the northern lights is aurora borealis and the southern lights aurora australis.

The lights are the result of solar activity interacting with the Earth’s magnetic field. It begins when the sun ejects a cloud of gas. Between two and three days later, the gas hits the magnetic field and generates charged particles that flow along the lines of the magnetic field in the polar areas of Earth. When these particles collide with oxygen and nitrogen atoms in the upper atmosphere the result is auroral light.

The lights can be seen anywhere, but they are most frequent at higher latitudes near the poles. The color is determined by the altitude. Blue violet/reds occur below 60 miles, bright green between 60-150 miles and above 150 miles (240 km) ruby reds appear.

Residents of Alaska may see the lights most nights. The lights are flashing during the day, but invisible to our eyes until the sky is dark. In addition to the common ripple appearance, the lights may also appear as pulsating globs or steady glows.

You can’t recreate the northern lights, but you can explain another way humans view light images with this simple experiment.

Experiment: How Do Mirrors Reflect light?

Materials: Aluminum foil.

Process: Place a 12 inch piece of foil; make sure it stays flat without wrinkles, shiny side up on a table directly in front of a resident. Have the resident see their reflection.

Now crinkle the foil and spread it out again in front of the same resident.

Result: The resident’s reflection will disappear. This happens because light reflects from a surface in straight lines. When the surface of the foil is wrinkled the reflected light bounces in all directions making the image of the resident seem to disappear.