What is the composition of neptune?

The first layer of Neptune is its icy atmosphere, which is mostly hydrogen and helium. The bluish coloration comes from traces of methane in the air, but the planet is a more brilliant hue than the dull blue of Uranus, which implies something else could be affecting it. read more

Atmospheric composition. Neptune's atmosphere is made up predominately of hydrogen and helium, with some methane. The methane is part of what gives Neptune its brilliant blue tint, as it absorbs red light and reflects bluer colors. Uranus also has methane in its atmosphere, but has a duller shading. read more

Atmospheric composition: Neptune's atmosphere is composed up of many gases. These gases include Hydrogen (80%), Helium (19%), and Methane (1.5%). Some of the minor gases include trace amounts of Hydrogen Deuteride and Ethane. When all these gases mix they create the blue color of Neptune. read more