Monday, July 25, 2011

0021: Aurora Borealis

"No pencil can draw it, no colors can paint it and no words can describe it in all its magnificence." 
- Mufassir Masum

Before you read on - check out this 1:55 minute video... isn't that just breathtaking and did you see those shooting stars! Ever since my 0015 post (Perspective & Wonder) I've been in awe of the space shuttle picture showing the Aurora. It seems so cool, so surreal and magical. So I did some research and was even more blown away! I can't even imagine seeing this in person - but I'm adding it to my list of must-sees! 

Cool Picture from a Free Wallpaper site
So... An Aurora is a natural phenomenon that often occurs in the polar ends of Earth. It looks like colorful clouds and rays of green and red (and sometimes blue) light that dance across the sky. The aurora borealis and aurora australis (Latin for "northern" and "southern" dawn, respectively) occur in symmetric ovals centered on the north and south poles. (Read more at NASA.)
Trivia Tidbit: In 1619 A.D., Galileo Galilei coined the term "aurora borealis" after Aurora, the Roman goddess of morning. He had the misconception that the auroras he saw were due to sunlight reflecting from the atmosphere. 

Picture taken from the ISS - May 2010
So, what causes these gorgeous dances in the sky? I've read several explanations but a lot goes over my head - you know, that same science jargon most of us didn't comprehend in grade school :-) So the short answer - it's the Sun's fault or rather the Sun's work of art... Here are some abbreviated tidbits from Encyclopedia of Earth - great site btw...

View of The Aurora from Space.
Courtesy of NASA

  1. The energy source for the aurora is 93 million miles from Earth at the sun. 
  2. The sun continuously emits charged particles. These charged particles make up the solar wind, which travels away from the sun through space at speeds of about a million miles per hour.                 *** Stay with me.... ***   :-)
  3. At Earth, the steady solar wind is deflected by Earth's magnetic field or the magnetosphere. The solar wind flows around our magnetic field much like a river flows around a stone. It also pushes on the magnetosphere and distorts it so the magnetosphere is stretched and pulled into a comet shape with a long tail trailing away from Earth on the side away from the sun.
  4. When there is a disturbance in the solar wind accelerated particles will travel down the magnetic field lines of Earth and collide with the atoms and molecules of the upper atmosphere.
  5. When the particles from the magnetosphere collide and finally release their energy and return to their normal ground state, they give up energy in the form of light. This is the light that we see from the ground as an aurora.

Phew! That took me a minute to grasp and a few to write... but if that's not going to stick, I hope you just appreciate the beauty of it. I think I could watch that video over and over again...

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