Atmospheric Spectral Shift

Why does the Sun seem red near the horizon? Why does the Moon do the same?  We know the Moon isn’t actually changing colour, and the Sun isn’t either.  So what is happening to the light? The first thing to note about the image above is that the size of the Moon doesn’t change, showing that the well-known ‘Moon Illusion,’ where the Moon appears larger near the horizon, is just that – an illusion.  The second is of course the gradual change in hue as the Moon rises. The reason for the colour shift really has nothing to do with the Moon...

A Sunny Cold Sunday is a Good Day to Find Sun Dogs

When the temperature is just right, and the sky is clear, you can see some amazing phenomenon from the Sun.  It isn’t your eyes playing a trick on you, it just means you’re seeing the right conditions for a really amazing experience. Sun Dogs, known scientifically as Parhelia, typically appear as two bright patches on either side of the Sun.  Occasionally they reveal rainbow colours in their pattern, but can be quite bright.  They are most easily visible when the Sun is low in the sky. Sun Dogs are made from the refraction of ice crystals in the upper atmosphere....