Neptune, blue color

Alkanes are widespread both on Earth and on other planets. The atmospheres of Jupiter, Saturn, Uranus, and Neptune contain large quantities of methane (CH4), the smallest alkane, which is an odorless and flammable gas. In fact, the blue colors of Uranus and Neptune are due to methane in their atmospheres. Alkanes on Earth are found in natural gas and petroleum, which are formed by the decomposition of plant and animal material that has been buried for long periods in the Earl s crust, an environment with little oxygen. Natural gas and petroleum, therefore, are known as fossil fuels. 

The outer planets contain smaller amounts of other gases as well, including methane, which is responsible for the blue color of Uranus and Neptune. 

The blue colors of Uranus and Neptune are caused by the presence of methane, a colorless and odorless gas, In their atmospheres. Natural gas—called a fossil fuel because It Is formed from the decomposition of plant and animal material In the Earth s crust—Is approximately 75% methane. 

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See also in sourсe #XX -- [ ]

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