Two unusual bright lights seen from passenger jet that just strangely winked out

I was in a window seat 10A on Delta flight 3760 from Minneapolis, MN, to Knoxville, TN.  We had just begun our descent over southern Kentucky, when I  saw two bright lights, slightly off white, over the left wing at what I would guess would be 1-2 miles away..  
At first, I thought it could be two other aircraft with their approach light on.  However, there were no red or green navigation lights and the brightness and separation did not change over time.  The two lights appeared to track along at the same speed as our aircraft.  
After watching these lights for about two minutes, one of the lights disappeared instantly.  I watched the second light and after about 10 seconds it also disappeared instantly.  
I've flown quite a bit and seen many aircraft and navigation lights and these did not look like anything I've ever seen.  As I exited the aircraft, I asked the pilot if he observed any unusual lights out the left side of the aircraft during the descent.  He said no and ! that there are a lot of lights out there.