I first observed the object traveling east in level flight. It then stopped and descended. I was parked on Virginia St., facing east in Berkeley CA, eating my lunch. Out of the corner of my left eye I noticed an object moving slowly across the sky.
I grabbed my phone and started recording video as the object stopped. It then descended and I lost sight of it behind the Hanson Aggregates plant. I waited to see if it would reappear, but it did not. The object was silent and travelled NE in level flight until it stopped and hovered.
That is when my video started. It descended at approximately the same speed as it traveled in level flight. I have never observed anything like this before.