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SUNSET PLANETS: Lately, have you noticed a pair of bright lights shining through the rosy glow of sunset? That would be Venus and Jupiter: the two brightest planets are converging in the evening sky. Look for them tonight: sky map.
AURORA STORM: It's over. A geomagnetic storm that began on August 24th when a coronal mass ejection hit Earth has subsided. During the storm, sky watchers saw bright auroras in Colorado, Utah, Wisconsin, New York and other US states.
Anthony Arrigo of Park City, Utah, reports: "I got a call from SpaceWeather Phone at 3:30 am." He walked out on his back deck and saw this:
"Even the really bright moon was no match for the auroras--for a little while," Arrigo adds.
August 2005 Aurora Gallery
LUNAR GREEN FLASH: You've probably heard of green flashes from the sun: Just as the setting sun disappears completely from view, a last glimmer sometimes appears startlingly green. But have you ever heard of a green flash from the Moon? Laurent Laveder of Bretagne, France, photographed one on July 20th:
Look carefully. The entire upper rim of this moon looks green, while the lower rim is red. This happens because our atmosphere acts as a giant lens and prism, splitting the "white moon" into its red, green and blue (RGB) components. The "green moon" hangs higher than the "red moon" by a very small amount--hence the green and red rims. (What happened to the blue rim? Click here.)
"Contrary to what many book and websites say, this effect is far too small to make a green flash," notes atmospheric optics expert Les Cowley. "Somehow that green rim has to be magnified. We need unusual air conditions--e.g., a layer of warm air close to the ground or, just below you, a temperature inversion layer. Light passing between these layers is bent and color separated more strongly, forming the 'inferior mirage' and 'mock mirage' types of green flash. Laveder's is an unusual variant of the latter."