Sunsets on Mars are Blue
On Mars, the daytime sky is pink. But at sunset? It turns blue. The same dust that makes Mars red all day long is what creates that cool blue glow around the sun as it sets. Space is full of beautiful surprises.
At sunset, go outside and look at the sky. What colours do you see? Most likely, you will see oranges, pinks, and reds spreading across the horizon.
Now imagine those colours in reverse.
Sunsets on Mars Are Different
On Earth, sunsets are warm and golden. The sky around the sun turns orange and red as the day ends.
On Mars, it's the opposite. During the day, the Martian sky looks pinkish-red. But at sunset, the sky around the sun turns blue.
Why Mars Has Blue Sunsets
It comes down to dust.
Mars is covered in fine reddish dust. This dust floats through the air and scatters red light across the whole sky during the day, giving Mars its familiar rusty glow.
But the same dust is very good at letting blue light travel in a straight line, close to the sun. So as the sun sinks toward the horizon, the light that reaches your eyes from that direction is blue.
On Earth, the opposite happens. Our atmosphere scatters blue light everywhere during the day, giving us our blue sky. At sunset, only the warmer colours make it through.
A Distant View
NASA's rovers have photographed Martian sunsets since 2005. Each image shows the same quiet blue glow settling around the sun as it drops below the horizon — a colour that would look completely at home on Earth, on the wrong planet, at the wrong time of day.
NASA Scientific Visualization Studio
