Clear blue sky. It was following a jet that had just taken off from PHL airport.

I was looking North/East. Round silver disk was following a jet that had just taking off from PHL airport. It was probably a quarter mile behind the jet. The jet was northbound, moving from my right to the left. It followed the jet for a few miles, then it suddenly dropped straight down, then disappeared. There were no lights, the sun was reflecting off of it. Very much in focus. It's size was a quarter of the jet. Then, for whatever reason, my eyes were drawn to the North, where I saw 2 more of the same disk following another jet heading West, they were 2 fingers apart. Then 'they' stopped and started moving in the opposite direction towards the North/East. One moved in a straight course, while the other moved erratically in all directions, keeping close to the other one. They were moving at a moderate speed. I followed them for 2 hand widths until they disappeared behind a tree. Mind you, I am 68, I do not drink, nor do drugs. I did not imagine these craft. You may contact me if you wish. Thanks.