Syzygy …

In case you missed last night’s lunar eclipse.

A lunar eclipse can only occur on the night of a full moon. The sun is on the opposite side of the earth. The photo was taken as the moon passed into the earth’s shadow. Light refracted through the earth’s atmosphere illuminates the moon and is reflected back to us. The colour is red for the same reason that a sunset is red – Rayleigh Scattering …

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).

You can work it out for yourself from the formula …

Let me know the answer.