I took this picture earlier in the summer. When the the moon is low down in the sky, the light from the moon comes through the atmosphere at an oblique angle. This means that it travels a longer distance through the air than if it had hit straight on. The light hits tiny particles in the air it is scattered. The short wavelength colours at the blue end of the spectrum are scattered first leaving the redder colours to reach us. Hence the moon looks pink. Incidentally, they say that the moon looks bigger when it is nearer the horizon but that this is an optical illusion.Thursday, 30 September 2010
Pink moon
I took this picture earlier in the summer. When the the moon is low down in the sky, the light from the moon comes through the atmosphere at an oblique angle. This means that it travels a longer distance through the air than if it had hit straight on. The light hits tiny particles in the air it is scattered. The short wavelength colours at the blue end of the spectrum are scattered first leaving the redder colours to reach us. Hence the moon looks pink. Incidentally, they say that the moon looks bigger when it is nearer the horizon but that this is an optical illusion.