Object pictured appeared on unmonitored camera; is it anomalous or an airplane?

One object entered and left an "unmanned" camera frame across four seconds, moving left to right. Its aspect or viewing angle remained the same throughout. It had two "headlights" which always faced the same direction towards the camera, and a single blinking light on its base. There was no apparent change in size to suggest advance or retreat, and it moved in the direction it was pointed. The seeming downward movement is misleading; the camera was facing about 85 degrees upward, so it was traversing the sky in a slightly curved fashion. No distance estimates are possible.