This snapshot of Neptune was developed from the last entirety planet images taken v the green and also orange filters on the Voyager 2 small angle camera. Image Credit: NASA/JPL.

You are watching: What gives neptune its blue color

Out of all the planets in the solar system, Neptune is the one the looks many peaceful. When seen v a telescope, the eighth and also most distant planet indigenous the sun appears sky-blue or together a uniform, peaceful ocean world that would have actually made the roman inn god the the sea proud.

In reality, Neptune is anything but peaceful and also its environment is actually largely made of three gases: hydrogen (80%), helium (19%), and methane (1%).

It’s actually clouds of methane gas that space responsible because that the far-off planet’s blue marble appearance. In spite of the reality it makes up a relatively tiny relationship of Neptune’s atmosphere, methane absorbs red wavelength of light and reflects blue light outward.

A far-off blue gem

Neptune is the just planet in the solar mechanism that isn’t clearly shows to the nude eye. Together such, the was among the last to be found in 1846 by Johann Galle, based upon mathematical predictions do by Urbain Le Verrier.

But throughout these early observations, astronomers had no idea what Neptune looked like.

The planet, i m sorry is around four times bigger than Earth, was an initial visited through a spacecraft in 1989 as soon as NASA’s Voyager 2 made a flyby. Voyager beamed back images mirroring Neptune’s ocean-like hue because that the an initial time. It was yes, really a stroke of luck the Neptune was so aptly named when astronomers might not have known the the world is every blue.

Neptune’s great Dark Spot, accompanied by white high-altitude clouds, as viewed by a Voyager spacecraft.Credit: NASA/JPL-Caltech.

Similarly come Uranus, Neptune is one-fifth hydrogen and helium by mass. The mass of the planet’s mass, however, is owed to heavier molecules such as ammonia, methane, carbon, oxygen, and also water.

Despite your similarities in size and composition, Neptune and also Uranus space distinctly colored. This is defined by different chemical materials in each of the planets’ upper atmospheres, specifically in the an international cloud deck.

Get more science news prefer this...

sign up with the ZME news for remarkable science news, features, and exclusive scoops. Much more than 40,000 subscribers can"t it is in wrong.

daily     Weekly

I have actually read and also agree come the state & conditions.

Neptune’s clouds are well-known to vary through altitude, just like on Earth. Methane clouds condense in the highest layers that the planet’s atmosphere because of frigidly cold temperatures. Further down, there may be clouds the hydrogen sulfide, ammonium sulfide, ammonia, and water. The blue-toned methane isn’t same distributed; ten to a hundred times an ext methane, ethane, and also ethyne deserve to be uncovered at Neptune’s equator than at its poles.

Being existing in the outermost great of the atmosphere, the most important compound that influences the shade of both planets’ atmospheres is methane. The greenhouse gas absorbs red light at wavelength of 600 billionths the a meter, reflecting earlier bluer light. Uranus, however, is an ext azure, blue-green in appearance early to an additional chromophore that Neptune appears to lack. This details chromophore hasn’t been determined yet for this reason the true nature the Neptune’s shade is quiet a mystery.

See more: What Is The Difference Between Pasta Sauce And Pizza Sauce, Easy Homemade Pizza Sauce (5 Ingredients!)


Tibi Puiu

Tibi is a scientific research journalist and also co-founder the ZME Science. That writes mainly about emerging tech, physics, climate, and space. In his preventive time, Tibi likes to make weird music top top his computer and groom felines.