In a 2014 study that used data from the Mars rover Spirit, Ehler and his colleagues found that Martian dust scatters light very differently than gas molecules do. "The reason for [the] blue sunset is the pattern in which light scatters off those [dust] particles," he said.

Why is the sunset blue?

Particles that are small compared with the light wavelength scatter blue light more strongly than red light. Because of this, the tiny gas molecules that make up our Earth's atmosphere (mostly oxygen and nitrogen) scatter the blue portion of sunlight in all directions, creating an effect that we see as a blue sky.

Why the sunset and sunrise on Mars is blue?

The bluish tinge of the sun is attributed to suspended dust particles in the Martian atmosphere. “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.