WHY DOES URANUS LOOK BLUE-GREEN?

Uranus is the seventh planet of the solar system and the 3rd of the gas giants. In 1781, William Herschel discovered this gas giant. Interestingly, he first surmised Uranus to be a comet. But he confirmed it to be a planet after several years. His nomenclature of Uranus was Georgian Sidus, after King George III. But the scientific community didn’t accept the name and gave the name of the planet as “Uranus”. However, ancient civilizations couldn’t observe this planet as it was really dim to see in the dark night sky.

THE REASON BEHIND URANUS’ COLOR:

The color of Uranus arises blue-greenish due to its atmosphere. Its atmosphere contains mostly hydrogen, helium and methane. This atmosphere is so similar to that of other gas giants such as Saturn and Jupiter. The main component that causes the color is methane.

HOW DOES METHANE HELP URANUS GET ITS COLOR?

Methane is present in the clouds of Uranus. It is more likely to absorb colors at the red end of the spectrum. All colors of light coming from the sun to fall on this gas giant. But it only absorbs the red end of the spectrum due to the presence of methane. Then, it is more likely to reflect backlight that is at the blue-green end of the spectrum. Therefore, this reflection of blue-green light makes the planet appear the same color.

MORE INTERESTING FACTS ABOUT THE PLANET:

(i) However, Uranus rotates around itself in a retrograde manner (opposite to the direction of rotation of earth).

(ii) At some point during its revolution around the sun, its pole directly faces the sun. As a consequence, it has to go through 42 years of sunlight straight, and also 42 years of darkness.

(iii) Voyager-2 is the only spacecraft to have visited this gas giant.

(iv) Interestingly, radioactive element Uranium was named after this planet in 1789.

More articles on radioactivity here

(v) Undoubtedly, it’s the coldest planet in the solar system with a minimum surface temperature of -224 degree celsius. More about really cold planets

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Uploaded by Bhautik Kapadiya 

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