Planets such as Mars and Jupiter have received a lot of attention from the space science community, but two other planets have not—data on Uranus and Neptune is scarce because no probes have been sent to study them. In a new effort, the researchers sought to learn more about both planets and specifically to determine why one of them has a darker blue hue than the other.
Researchers from the University of Oxford said that the answer lies in a haze layer in the atmosphere, which is two times thicker in Neptune. Study lead author Patrick Irvin said that this layer is called the Aerosol-2, which looks whitish at visible wavelengths and acts to lighten Uranus, which explains why the seventh planet in the Solar system has a paler shade of blue compared to Neptune.
The researchers created a model that represented the atmospheric conditions on both planets and it showed Uranus’ atmosphere to be thicker than Neptune’s, which is why Neptune is darker blue than Uranus—and both are blue because methane reflects blue light. The researchers also found that Neptune is not as uniformly colored as previously thought.