appeared about 39 degrees above horizon. seemed above Napa Valley 60 miles south of our location. Went straight down travelling say 1,000 mph. light extinguished after 3 seconds 12 degrees above horizon. mile wide if it was 60 miles away over Napa alley. light looked like an azure blue penny (flat) shaped object with a black gap above it and white crescent shape above the gap. Like a half curved circle of white crescent light above the flat blueish green penny shape. Not a shooting star. Appeared, went straight towards the ground, no tail at all and disappeared. Very difficult to judge width, length, size of object. Very impressive.