"In this case, there were two airplanes coming towards us at the same time, 1000ft below and above. Sandwiched in between, the exposure time of 6 seconds drew their navigation lights as long colorful streamers. As a gesture of goodbye, the pilot above switched the landing lights on, adding two more yellow trails before it disappeared from sight. Literally, like ships passing in the night. "And to add some depth to the shot, the Moon was quite accommodating to create long Moonlight shadows of their contrails in the clouds below." Christiaan is one of the world’s leading aviation photographers and more of his work and more close encounter (s) can be found here. You can follow Christiaan on Instagram here: @jpcvanheijst