Mars: Nasa's Perseverance rover captures a rare blue sunset on the Red Planet

A rare picture of a strange blue sunset has been captured on Mars, revealing more about the planet's physics.

Nasa's Perseverance Mars Rover captured the image on its 933rd Martian day, just as the sun began to set using its navigation camera, located high on the rover’s mast aiding in driving.

The image, which Nasa gained on Thursday (5 October, revealed the horizon to be in a cool, blueish-green highlighting how the physics of light scattering on the Red Planet, and how it contrasts with a similar phenomenon on the Earth.

On Earth, the sunset is often an orange hue, and this occurs when different wavelengths of light from the Sun enter the atmosphere, and are scattered by tiny particles including gasses like oxygen, nitrogen, carbon dioxide, and water vapour as well as other particulate matter.

The daytime blue occurs when a planet’s side is closer to the Sun. Blue light travels in shorter waves and is scattered making the sky appear blue.

But, during sunrise and sunset, the sunlight travels more distance in the atmosphere which causes light with shorter wavelengths, including violet and blue to be scattered away, leaving only the orange and red light to reach the eyes.

atmospheric scientist Mark Lemmon from the Texas A&M University in the US explained previously: "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."

Mars's atmosphere is around 1% of Earth's thickness, and the planet is around 50% further from the Sun than the Earth. During the day, the red planet gets its red hue because light from the Sun interacts with large-sized iron-rich dust particles on Mars, and the dust scatters the lower-frequency red light.

When it comes to the Sun setting, light has a longer distance to travel and leaves the sky a blue colour. These images help scientists study the differences between the Earth's atmosphere and Mars'.