3 people clearly see large saucer shaped object 1/2 mile away

We were traveling South on N. Livermore Ave heading towards Portola Avenue.  I was in the passengers seat and spotted a saucer shaped object, about 1/2 mile away and 1/2 mile up in the sky.
It was stationary.   It was unobstructed.  Clear as could be.  Silver in color with many lights circling around the middle.  It made no noise. 
We pulled over, got out of the car and stared at it. I would say it was roughly 50 yards long and 20 yards high. The colors seemed to be unfamiliar.
After just sitting in one place for 4 minutes it moved, at an angle, about 1 mile away, in 1/2 a second.  Still no noise.  It moved about 3 more times, faster than anything I have ever seen, even to this day.  Finally it sped away and was out of sight in 1 second.
After it left someone said to not say a word, that we should drive back home and each write down what we saw. SO, we did.  And without communicating a word regarding what we saw, we each wrote down the exact same thing.
We were never scared and it didn't appear to notice us. It was clearly something from somewhere else.
Witness indicates that the date of the sighting is approximate.  PD