Astronomy Picture of the Day

Explanation: If you tried to enter this hall of fog, you would find it dissipates around you. The hall is actually an the mountain from which this picture was taken. Known as "the glory", the phenomenon is frequently seen from airplanes. The ring's center is not visible, but if it were, the shadow of the observer would appear. This shadow would likely change as clouds passed, creating a faux moving giant known as the Brocken Spectre. Pictured above, several concentric rings of the glory appear to create a hall for this mountain king. The cause of the glory has only been understood recently and is relatively complex. Briefly, small droplets of water reflect, refract, and diffract sunlight backwards towards the Sun. The phenomenon has a counterpart in astronomy, where looking out from planet Earth in the direction opposite the Sun yields a bright spot called the gegenschein.