The sunset on Uranus fades from a bright blue to royal blue with hints of turquoise, according to NASA scientists who have simulated sunsets on other planets and moons.
Geronimo Villanueva, a planetary scientist from NASA's Goddard Space Flight Centre, created animated simulations of sunsets on Earth, Venus, Mars, Uranus, and Titan while building a computer modelling tool for a possible mission to Uranus.
Videos of the simulations were released by NASA this week using the known colours of the sky on Uranus and other worlds.
The simulations are shown from the perspective of someone on these worlds during sunset.
According to NASA, during sunset, photons get scattered in different directions as these worlds rotate away from the Sun's light.
This results in the changing colours shown in the simulations.
"When sunlight — which is made up of all the colours of the rainbow — reaches Uranus's atmosphere, hydrogen, helium and methane absorb the longer-wavelength red portion of the light," a statement from NASA says of the simulation.
"The shorter-wavelength blue and green portions of light get scattered as photons bounce off the gas molecules and other particles in the atmosphere.
"A similar phenomenon makes Earth's sky appear blue on a clear day."
A halo of light is produced on both the hazy Earth simulation and Mars because of the way light is scattered by particles — such as dust or fog — that are suspended in the clouds.
The Mars sunset turns from a brownish colour to blue because Martian dust particles scatter the blue colour more effectively, according to the statement.
The simulations were created to validate the accuracy of Dr Villanueva's computer modelling tool, which NASA says would be a valuable instrument in any mission to Uranus.
"One day, a probe could descend through the Uranian atmosphere, with Villanueva's tool helping scientists interpret the measurements of light that will reveal its chemical makeup," the statement read.