Photographer Simon Roberts took to the skies above the North Pole to shoot the sunset in each of the Earth's 24 time zones over the course of 24 hours. Above you see a composite of 24 of the photographs spliced together.
The whole Chasing Horizons project is really an advertisement for Citizen watches. Head over to their site to see how Roberts and his pilot pulled off the stunt. There you an also explore an interactive version of the composite above. Each of those slices expands to a full size image from the project. (You'll have to scroll through a bit of narrative to get to the goods, but it's worth it.)
They flew over the North Pole because the distance between time zones is very short there and the aeroplane can actually keep up the linear velocity of Earth — while the angular velocity is the same through Earth, the linear velocity changes. At the Equator you would need to fly at more than 1600km/h.