Green flying saucer over San Francisco Bay on Dec. 2017

On December 2017, a man took a picture of a green flying saucer floating over San Francisco Bay, California.

Witness report:

On Dec. 22,2017 at approx. 0750 I was texted by a Coworker a picture he just took of a green object in the sky over the San Francisco bay approx. S.E. My coworker took the photo from the roof of our 43 story office building while doing his daily rounds (checks). As he was taking a picture of the sunrise he noticed the green object. He saw the object for about 15 Minutes. I did not notice the text until about half an hour later, so by the time I was able to get to the roof the glow was gone. While later looking at the picture on his phone my coworker showed me that the object darted around, but (live Pic on IPhone) but it was not visible to human eye at the time. Please let me know what you think?