Portal:Astronomy/Picture/20 July 2005
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![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Reflection.nebula.arp.750pix.jpg/300px-Reflection.nebula.arp.750pix.jpg)
The hot blue star Rigel illuminates this reflection nebula in the constellation of Orion. Interstellar dust preferentially reflects blue light in a process known as Rayleigh scattering, which gives reflection nebulae a characteristic blue colour. Skies on Earth are blue because of the same process.