During a night flight, you observe steady red and green lights ahead and at the same altitude. What is the general direction of movement of the other aircraft?

Explanation

An aircraft's red position light is on the left wingtip and the green one on the right wingtip. If you see both red and green at once, ahead and at your altitude, you are looking at the aircraft from the front, so it is approaching head-on. An aircraft flying away would show its white tail light.