For years, scientists have wracked their brains trying to figure out why Neptune is bluer than Uranus. In fact, the two planets are similar in so many regards that many refer to them as twins. Despite those similarities, though, Uranus has always looked a bit bleached out compared to its fellow blue planet. Now scientists may have finally figured out why.
Why Neptune is bluer than Uranus
For decades, scientists have pondered over the likeness and differences between our Solar System’s two ice giants. As the furthest planets from our Sun, being able to study them in-depth isn’t easy. NASA’s Voyager 2 spacecraft flew by the planets in the 1980s, giving us our first properly side-by-side of the two planets. Since then, we’ve been trying to figure out why Neptune is bluer than Uranus.
After almost 30 years, scientists may have discovered the answer. According to a group of researchers, the color difference is so stark because of atmospheric conditions. The researchers published a study with their findings in the Journal of Geophysical Research: Planets this month. Those findings are based on observations gathered by space and ground-based telescopes.
They used the Gemini North Telescope and NASA’s Infrared Telescope Facility, as well as the Hubble Space Telescope to create a new model based on observations of the two ice giants. Then, they compared the two’s atmospheric conditions and properties. Based on those comparisons, the researchers say Neptune is bluer than Uranus because of a haze that covers the latter.
This haze, the researchers say, also exists on Neptune. However, it is thicker on Uranus because the planetary atmosphere doesn’t disperse it. By removing the haze from the observational models, the scientists say that Uranus and Neptune were the same color blue.
Getting a better look at Uranus
Of course, we could learn even more about why Neptune is bluer than Uranus as we study it more. Science advisors have already made a big case for studying Uranus better in the coming years. Outside of the color differences, too, there is also evidence that Uranus was devastated by a massive object sometime in the past.
With more in-depth studies, scientists could learn more about that impact, as well as what caused it. And, of course, there’s just the general curiosity of what makes these ice giants the way they are. Sure, we know that their distance from the Sun plays a part. But, being able to study their atmospheres more in-depth could tell us even more.