Saw 2 very high aircraft flying circular patterns.

I was the Capt.on southwest 1878 Atlanta-Baltimore.5-2-22.We were level at 39000 ft.A light very high in the sky north of our position caught my attention.I watched it for several minutes and noticed there was another light that seemed to be traveling with it.THe first officer and I watched the light for 15-20 mins.The lights were at an extremely high altittude.I dont think they were conventional aircraft because of their ability to both fly and turn at such high altittudes.The aircrafts circular patterns continued to move to the northeast.The airtraffic controllers said their primary radar was turned up to 99000ft and they didnt see anything.As we begun our descent into Baltimore the aircraft continued to the northeast and we lost sight of them.