Spherical-shaped UFO sighting in Almaden Quicksilver Park, San Jose, CA

I was hiking with my daughter in Almaden Quicksilver Park, San Jose. This is next to Mnt. Umunhum, where an old Air Force base resides on top of the mountain. The large rectangular building on top of the mountain is very prominent and often referred to as "the cube". My daughter and I were looking at one of the huge power line structures just off the trail. My daughter walked off the trail, toward the structure, while I looked up at the birds sitting on top of it. I believe we were facing south and part of the sky was in view but there were also trees partially blocking the view as well. I saw a bright spherically-shaped object flying right to left at what appeared to be a very fast speed. The object appeared to be emitting a bright white light all around it, yet had a slight silver shimmer to it as if the sun was also partially reflecting off of it. My daughter did not see the object from her vantage point. We walked a few yards down the trail whe! re we could get a good view of the horizon (no trees in the way) but the object was long gone. I wish I had my phone out to take a video but it was gone in a matter of seconds. It was definitely not a plane, not a drone, and not a bird.  It is difficult to determine how large the object was. It looked extremely high-tech.