I was standing out in my front yard at about 10 pm looking at the stars in Northern California 1500 ft elevatiom in the mountains. Being able to see so many stars I always try to see something stand out when this bright light bigger and brighter than any star out came fly out from behind a mountain NE of me. It proceeded E going up and down back and forth(front and backward) when all of a sudden 8 to 10 helicopters and planes appeared behind it trying to fallow it it seemed. Though the 8 to 10 small dots that were blinking red lights like usual planes at night couldn't keep up with the object in front of them. Then after a few minutes the big solid light disappeared behind another mountain just like the planes did. This is a United States Air Force Base in the same direction my siting happened. Therefore making me belive that there really was something worth chasing I'm the sky that night.