Tonight is the Persian Festival of Autumn (called "Mehregan" in Farsi). The autumnal equinox has occured tonight at 11:09 pm ETS. Tonight, the last day of summer 2010 in the northern hemisphere, also coincides with a full moon. This is a rare event which happens every 20 years. Tonight the moon looks abnormally large and yellowish. At the sunset time, the moon light and the light of sun set were mixing together and created a beautiful twilight glow. Happy Autumn!