I was in Millbrae, CA (near the Burlingame border) walking my dog just before 10:30p. I happened to look up towards the SFO (San Francisco) airport inbound flight pattern (south of the airport), and just behind/above the power lines across the street, where I quickly caught a glimpse of a bright red light (with some white around the edges) in what appeared to be a chevron or arrow shaped trail pointing straight up into the sky. The shape was not solid, allowing me to see the dark sky through it, so I thought of it as a trail from an unseen object upon first glance. It appeared to be some distance away (miles) but inside the atmosphere.
I do not believe I actually saw it appear, because as soon as it caught my eye, it simply blinked out of existence. There was no fade or gradual dimming like I’ve seen from meteor/asteroid or rocket contrail, and the direction of the foci (point of the arrow/chevron) was straight up, which is normally opposite direction of either of these phenomenon.
It was definitely like nothing I have seen before, so I was surprised. I immediately thought it was a rocket contrail, but the light just disappeared like someone flipped a switch off. There was no motion to the shape itself. It stayed in the same position from the time I first saw it, until the time it disappeared (approx. 2 seconds). I searched the sky to look for any cause, or reappearance for several minutes, but saw nothing similar or related.