Looking Up?!

Normally when I see a bald eagle circling overhead it is always looking down toward the water for a potential meal opportunity.
I could not figure out what this eagle I saw today was looking up at. Usually the eagle is already flying higher then most other birds around the marsh area.
Perhaps it had seen another eagle far off (or up) a ways. A new bald eagle would be seen as a threat and be treated as an intruder.
But just because I didn't see anything it does not mean that our sharp eyed friend missed whatever else was in the sky.