APOD: 2002 November 10 - A Green Flash from the Sun     Explanation: Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green. The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds.     http://antwrp.gsfc.nasa.gov/apod/ap021110.html     tags: nasa sun greenflash