Red/orange noiseless lights in formation at low altitude.I was closing my bedroom window when I noticed a very bright red/orange light coming over Mount. Tamapais (from a westerly direction). It was too low to be a plane, so I ran outside to the front yard, and looked up the street towards the mountain. There I saw at least 5 more of the same craft, slowly hovering, moving East, over the valley where we live. More appeared over the course of the next 5 minutes. They were in formation, moving towards us, like they would land soon in the street in front of us. My neighbors were also outside observing the lights. They were noiseless, moved always in formation, and in the next 5 minutes, seemed to move South, and disappear. My husband used binoculars, and said they looked "diamond" in shape, said it was hard to define the shape. Very bright, deep, orange/red.