Sunset over Ares Vallis - Sol 13 (GIF-Movie - False Colors; credits: NASA)

Caption NASA:"Animation of the Martian Sunset.
This movie is made from 9 images of the twilight following Sunset over Ares Vallis. The images are enhanced in order to show the very subtle features in the haze, which are probably caused by layers that are slightly dustier than the surrounding air. The color is not the true color of the sunset - that is shown in other images.
At the beginning, the Sun is on the horizon just to the right of the frame, and it sinks during the next hour. At the time of the last image the sky is only 1% as bright as at the beginning, but the IMP can easily adapt to the darkness and return these pictures. Because there is so much dust extending high into the Martian Sky, the Sky stays bright for more than an hour after sunset".