Bright light in the sky, suddenly took off.

I was in my backyard after I let my three dogs outside before going to bed. In the sky, a bright, perfectly circular light appeared, a light that at first appeared to be a plane in the sky. It got so bright that it lit up the entire sky, stationary, for approximately three seconds. My three dogs (who were in the backyard) stopped what they were doing and looked up and stared. Then the bright light suddenly took off like a shooting start toward the east.