The Strange Sensory Theater of a Total Solar Eclipse

While crowds watch the sky, radio operators listen for changes in an invisible region far overhead. Solar ultraviolet radiation normally maintains electrically charged layers in the ionosphere. When the Moon blocks that energy, ionization declines and the effective reflecting properties of those layers change, almost as though a small patch of nighttime atmosphere were moving across the daytime Earth. Some high-frequency signals may travel farther, while others weaken, fade, or follow different paths.