A Look at the Martian SkyThe sky of Earth is blue. But, as shown in this image, on Mars, the sky is darker with a slightly pink overtone.
The light in the atmosphere comes from the Sun. Sunlight appears to have no color at all, but is actually a mixture of all of the colors of the rainbow. When sunlight strikes air particles (which are very small), the light itself is deflected (scattered) in all directions, forward, sideways, and backwards.
Air molecules scatter some colors of light better than others. Blue light is scattered the most and red light is scattered the least. Since the blue rays of lights are scattered the most, they reach our eyes from all directions and we see more blue than any other color. On Earth, this means that the sky looks blue.
In this image, the Martian sky appears pink and a little bit dark at sunset. The sky appears darker because the thin atmosphere does not contain enough molecules to scatter the same amount of light we are used to seeing on Earth. The sky appears pinkish because there are many rust-colored dust particles in the atmosphere.