The sunset is blue, fading to pink as you raise your gaze upwards. This is the opposite of what you’d expect from a normal sunset, which starts out pinky-orange and moves upwards to blue. So why is this sunset different?
“Because we’re not on Earth. This is a Martian sunset.” How brilliant is that? On Mars, each and every sunset is blue. Why is this? The answer lies in the air and dust of Mars. Ezra Block and Robert Krulwich over at NPR explain this phenomenon.
The gasses in the air on Mars are different to those found on Earth, and the Martian air is filled with extremely small dust particles. These are the key to the blue sunsets, as the dust scatters light differently compared to the dust on Earth. “Martian dust is exactly the right size to absorb the blue wavelengths of light and scatter red wavelengths all over the sky. That’s why if you are standing on Mars and look away from the setting sun, most of the sky is rosy, pink, and various shades of red.“
This is the exact opposite of what happens on Earth. The wonders of light, dust, and air. Onwards!