Uranus and Neptune are some of the most overlook planets in our solar system. The blue duo, about four times as big as the Earth, share the same blue colour, although they differ in shade.
A new study claims to have an explanation for the difference in the hues of the farthest planets of our solar system.
Scientists also found dark spots on Neptune indicating that the eighth planet of our solar system is not as uniform in colour as previously thought.
Using data from NASA’s travelling probes Voyager-1, Voyager-2, Hubble Space Telescope, and multiple ground-based telescopes, scientists create models to represent the atmospheric conditions on the dark-blue planet duo.
Scientists found that the reason Uranus’s darker blue than Neptune is because it has a thicker atmosphere compared to Neptune.
The dark spots on Neptune are highly concentrate materials in the planet’s upper atmospheric layer.
Scientists have known for a long time that the reason for Uranus and Neptune’s blue colour is the presence of methane in their atmosphere.
Methane absorbs infrared light and reflects blue light.
It makes up about 2 percent of Uranus’s atmosphere and about 1.5 percent of Neptune’s atmosphere.
Using the models create for the study, scientists were able to tell that both planets have nearly equal atmospheric pressure and both have large amounts of ice, hydrogen sulphide, and resulting photochemical haze.
As per the study, both planets have photochemical haze produce in their upper atmospheres which steadily mixes down to the lower layers forming a thin and stable atmospheric surface.
The atmospheric methane then condenses upon these haze particles and snows out the base of the new layer, which falls to lower and warmer levels.
The dark spots seen on Neptune are perhaps the darkening or clearing of this lowest haze layer.
The darkening can also be occasionally seen in Uranus, say scientists.
Scientists believe that their work could provide a platform for studying similar planets that are orbiting stars other than our sun.
The study publish on the arXiv preprint server was submit on 12th January 2022 to the Journal of Geophysical Research : Planets and is yet to be publish.
