I saw three strange lights moving very fast across the sky in formation but not perfect unison (separate objects)

My coordinates at the time of the sighting according to google maps: (45.5248002, -122.6920721)  Lying on my apartment’s balcony with my feet pointing north, I saw three dim (almost hazy) white lights moving silently at approximately equal speed from the southwest to the north, passing through the handle of the Big Dipper.
 They were almost equidistant from each other in a diagonal line but the one furthest to the right broke formation slightly. It looked like it’s position wobbled in relation to the others. This made me realize that they weren’t quite moving in perfect unison and seemed like three separate objects.
 They were moving at high speed. The speed indicated to me that if it were a plane, it would have to be close to the ground in order to appear as if it were crossing the sky so quickly. However, it produced no sound audible to me and did not visually appear close to the ground.