Audible dot com is the leading provider of downloadable digital audio books and spoken word entertainment. Audible has over one hundred thousand titles to choose from to be downloaded to your iPod or MP three player. Go to audible podcast dot com slash brain stuff to get a free audio book download of your choice when you sign up today. Welcome to Brainstuff from Hastaff Parks dot com where smart happens. Hi. I'm Marshall Brain with today's question, how does the Aurora
borealis or the Northern lights work? The Aurora borealis has always fascinated mankind, and people even travel thousands of miles just to see this amazing light show in the Earth's atmosphere. The aurora's both surrounding the Northern Magnetic Pole and the Southern Magnetic Pole, occur when highly charged electrons from the solar wind interact with elements in the Earth's atmosphere. Solar winds stream away from the Sun at speeds of about
one million miles per hour. When they reach the Earth some forty hours after leaving the Sun, they follow the lines of magnetic force generated by the Earth's core and flow through the magnetos sphere, a tear drop shaped area of highly charged electrical and magnetic fields. As the electrons enter the Earth's upper atmosphere, they encounter atoms of oxygen and nitrogen at altitudes from twenty to two hundred miles
above the Earth's surface. The color of the aurora depends on which atom is struck and the altitude of the meeting. Green auroras mean that an oxygen atom up to a hundred and fifty miles in altitude has been hit by an electron. Red auroras mean that an oxygen atom above a hundred fifty miles in altitude has been struck. A blue aurora means that a nitrogen at them up to sixty miles in altitude has been struck, and a purple or violet aurora means that a nitrogen atom above sixty
miles in altitude has been struck. All of the magnetic and electrical forces react with each other in constantly shifting combinations. These shifts and flows can be seen as the auroras appear to dance, moving along with atmospheric currents. The auroras generally occur along the auroral ovals, which center on the magnetic poles of the Earth. And roughly correspond to the Arctic and the Antarctic circles. There are times, though, when the lights are further south, usually when there's a lot
of sun spots. Sun Spot activity follows an eleven year cycle, and the next peak will occur in two thousand and eleven and two thousand and twelve, so opportunities to see auroras outside their normal rain should be good. There are many stories about sounds associated with auroras, but there are no recordings of these sounds. Scientists can't agree on what would produce sounds during an aurora. Do you have any
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