NASA’s Curiosity Rover photographed this view of the sun setting from its 956th Martian day on Mars. Notice that the sunset from Mars appears blue.

The above image actually consists of a sequence of four images captured over a span of 6 minutes, 51 seconds. Check out the full GIF below.

Said Mark Lemmon of Texas A&M University, College Station, who planned the Curiosity mission: “The colors come from the fact that the very fine dust is the right size so that blue light penetrates the atmosphere slightly more efficiently.

“When the blue light scatters off the dust, it stays closer to the direction of the sun than light of other colors does. The rest of the sky is yellow to orange, as yellow and red light scatter all over the sky instead of being absorbed or staying close to the sun.”

So cool, at least nearly as interesting as the heart-shaped craters also discovered on Mars.

Why is the Mars sunset blue?

Unlike Earth’s sunsets, Martian sunsets display an ethereal blue hue. Fine dust particles in the Martian atmosphere cause blue light to penetrate more efficiently, creating this intriguing phenomenon.

The blue light scatters and dominates as the sun sets, while other colors absorb or scatter in different directions. Mars’ unique atmospheric conditions create this breathtaking display, providing a glimpse into the planet’s distinctive weather patterns and atmospheric composition.

Sunsets on Mars versus Earth

Aspect	Earth’s Sunsets	Mars’ Sunsets
Color	Orange, red, pink, purple	Ethereal blue near Sun, yellow to orange in the sky
Atmosphere	Nitrogen, oxygen, water vapor, pollutants	Thinner, mostly carbon dioxide, fine dust particles
Effect of Dust	Intensifies colors, more vivid sunsets	Scatters blue light, causes blue tint
Scattering Phenomenon	Rayleigh scattering, shorter wavelengths scatter	Blue light penetrates more efficiently
Summary	Warm and vibrant hues	Calming blue tones, unique atmospheric makeup

This article was originally published August 19, 2019. Updated August 23, 2023.