Stationary bright light over foothills stays still for 10 seconds and then flies out of sight in less than a second.

The night was completely clear with no moon out. I had gone into our back yard on the east side of our house and noticed a bright light above the foothills to the east about 7 or 8 miles from me. The light looked like an aircraft landing light, staying stationary in the air, about 1000 feet above the hills. I stared at the light because it wasn't moving and wondered why it was so still if it were a small airplane. It was too bright to be a star. All of a sudden, the light took off with no accelleration toward the north. The best way I can describe how fast it took off is if you were looking at one frame of a moving film and then started the movie, you would see instant motion. The light flew horizontally and covered about 10 miles less than a second. As it flew further to the north it got farther away and I couldn't see it anymore.
Date is approximate.  PD