Eerie Aurorae

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[SFX: Saturn aurora]

Those who've seen the aurorae -- the shimmering curtains of color known as the northern and the southern lights -- describe them as beautiful -- and eerie. They dance and ripple across the sky, sometimes changing colors.

It turns out that the aurorae sound eerie, too. [bring up SFX] They generate radio waves that are recorded by spacecraft. Scientists convert the radio waves to sound. These sounds came from the planet Saturn, which also has aurorae. [more SFX]

The aurorae on all the planets are produced when particles from the Sun spiral toward the planet's magnetic poles. They strike atoms and molecules in the upper atmosphere, causing them to glow. On Earth, most of the glow is in the form of visible light. On Saturn and Jupiter, it's in the ultraviolet.

On all three planets, though, they produce radio waves. And recent observations of Earth's aurorae by a set of European spacecraft suggest that these waves could be used to study planets in other star systems. The radio waves travel out in tight beams; radio telescopes could record the beams as they come and go, revealing how fast the planet spins. So we may someday learn about alien worlds by listening for the eerie sounds of their own northern and southern lights. [bring music up]

Script by Damond Benningfield, Copyright 2008

For more skywatching tips, astronomy news, and much more, read StarDate magazine.