An interesting post at http://malagabay.wordpress.com/2013/04/15/why-the-sky-is-blue/ … which according to Wikipedia, and various others, the sky is blue because air scatters short wavelength light more than longer wavelenths. The human eye perceives the colour blue when looking at the sky rather than at the Sun (http://en.wikipedia.org/wiki/Diffuse_sky_radiation … which implies the Wikipedia editor has forgotten that Indigo and Violet have shorter wavelengths than blue light. In the mainstream hypothesis the sky should be violet rather than blue as it has the shortest wavelength – but it is blue. Why?
This is an excellent and thought provoking post which I hope you enjory reading – by clicking on the link above. The key to understanding the blue sky, the link continues, was estimated by Ralph Rene (1998) when he realised the Earth's atmosphere flouresces. Pictures of the Earth from space show the Earth in a thin band of cobalt blue – the cause is electrical energy from the Sun (see www.ralphrene.com) – the solar wind.
In another post Tim Cullen notes the same thin band of blue surrounding Titan. Lots of electrical energy on Saturn. See http://malagabay.wordpress.com/2013/05/08/titans-variable-electromagneti… … Titan spends 95 per cent of its time within Saturn's magnetosphere which shields it from the solar wind – but Titan also has a magnetosphere. The brightness cycle of Titan seems to be driven by charged particles from Saturn's magnetosphere – which is a similar mechanism to the solar wind affecting the magnetosphere of the Earth, and synchronises with the Sun's magnetic cycle of 22 years.