Search This Blog

Monday, May 10, 2010

Northern Lights

I have always been fascinated with the Aurora Borealis, also known as the northern lights.  It has been my dream to go to Alaska or somewhere in the northern latitudes and see them someday.  Citizens of Fairbanks, Alaska, at a latitude of 65 degrees north, can see the Northern Lights an average of 240 nights a year!

One night a few years ago, I went outside in my back yard and was a little mystified at what I saw in the sky. It was well past the sunset, but the sky in the West had streaks of red as if the sun were just going down.  And the sky in the East had streaks of red as if the sun was about to rise. It was absolutely beautiful! I just stood outside and gazed in wonder at the spectacle.  In fact, it took me a while to figure out what it was that I was seeing. Those northern lights coasting farther south than usual.

I live in Pleasant Grove, Utah, (about 30 miles south of Salt Lake City) at a latitude of 40 degrees North.  Although it is not normal for the northern lights to drift this far, during very large auroral events, they have been seen as far south as Mexico City.  It is a rare sight there.

There is a podcast that is enjoyable to listen to called The Naked Scientist.  It sounds intriguing, but there is nothing a child shouldn't hear in this podcast.  The other day they described what happens when the northern lights are visible.

The sun has bursts of energy called solar flares.  A solar wind carries these charged energy particles from the sun and they collide with the Earth's magnetic field.
This collision produces the lights.  It generates as much as a million megawatts of electricity.  One megawatt will supply enough power to sustain 1,000 averages households for one year.  So a million megawatts would power one billion average households for one year!  A small part of this electricity causes discharge in the upper atmosphere and creates light much in the same way as a neon sign creates light. The kind of atom in the solar wind determines the color. 

*The aurora in the southern hemisphere is known as the Aurora Australis.  It is almost a mirror image of the Aurora Borealis.
*Auroras have also been observed on Jupiter, Saturn, Uranus, Neptune, Mars, and Venus.
*The aurora gets its name from the Roman goddess of dawn.

Now you have heard something interesting. 


  1. You never cease to amaze me. I love it. K8

  2. Does longitude matter? I mean, you can see them at a latitude of 40º N in Utah, can you see them at 40º N in China? I wish I would have looked for the Northern Lights while I was in St. Petersburg.