Neptune is about 17 times more massive than Earth and shares with our planet a deep blue color — but for different reasons.
"In our case, the color comes from a combo-plate: Our oceans absorb red light and reflect away the blue, plus our atmosphere scatters blue light," Slooh astronomer Bob Berman said in a statement.
"But Neptune's color is due to methane, what we on Earth call natural gas. It absorbs the sun's red light but bounces the blue back to our eyes," Berman added. "The result is arguably the most deeply colored planet in the solar system...
Sometimes thick pollution causes the sky to appear white, but a clean sky is blue.
In many places air pollution causes haze that causes the sky to appear pale blue or even milky white. Layers of air pollution can cause the sky over the horizon to appear brown or gray. Air pollution can take many forms. It can be gases and vapors, mists and droplets or tiny particles of carbon or other materials.
originally posted by: Yeahkeepwatchingme
It's interesting. When you think methane OP do you think of the Jumping Jack Flash hypothesis? That is scary stuff and this instantly reminded me of that theory.
originally posted by: AlphaHawk
a reply to: luxordelphi
My sky is a rich blue and never had any sort of trails to either make it that way, or make it paler, whatever theory you're trying to push..
originally posted by: Zaphod58
a reply to: luxordelphi
I drive all over the country, and I see rich blue skies everywhere I go. The only times I see white skies is when the clouds move in. Every other time it's a beautiful blue.
For some astronauts, that thin blue line has appeared quite vulnerable. Many have noticed palls of haze lingering over parts of the world, the result of millions of tiny particles drifting in the atmosphere. Aerosol particles, which can be either liquid or solid, obstruct sunlight and cause distinct and vibrant features to blend into a hazy, featureless mélange of gray
A portion of the beam of light coming from the sun scatters off molecules of gas and other small particles in the atmosphere. Here, Rayleigh scattering primarily occurs through sunlight's interaction with randomly located air molecules. It is this scattered light that gives the surrounding sky its brightness and its color. As previously stated, Rayleigh scattering is inversely proportional to the fourth power of wavelength, so that shorter wavelength violet and blue light will scatter more than the longer wavelengths (yellow and especially red light). However, the Sun, like any star, has its own spectrum and so I0 in the scattering formula above is not constant but falls away in the violet. In addition the oxygen in the Earth's atmosphere absorbs wavelengths at the edge of the ultra-violet region of the spectrum. The resulting color, which appears like a pale blue, actually is a mixture of all the scattered colors, mainly blue and green. Conversely, glancing toward the sun, the colors that were not scattered away — the longer wavelengths such as red and yellow light — are directly visible, giving the sun itself a slightly yellowish hue. Viewed from space, however, the sky is black and the sun is white.