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Nature3 February 2005

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As seen on radio

The powerful radio transmitter array at the HAARP observatory near Gakona, Alaska, is designed to transmit a narrow beam of powerful radio signals into the sky. The response to this intervention reveals details of the chemistry and physics of the ionosphere. One such experiment carried out in March 2004 had an unexpected outcome, inducing artificial optical emissions bright enough to be seen as small speckles by the naked eye. This occurred not in the quiet ionosphere, but in the midst of a pulsating aurora, and represents features much smaller and brighter than ever observed previously.

letters to nature
Creation of visible artificial optical emissions in the aurora by high-power radio waves
TODD. R. PEDERSEN & ELIZABETH A. GERKEN
Nature 433, 498–500 (2005); doi:10.1038/nature03243
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news and views
Atmospheric physics: Seeing the light
KARL ZIEMELIS
Nature 433, 471 (2005); doi:10.1038/433471b
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3 February 2005 table of contents

  
  © 2005 Nature Publishing Group