The characteristics of the radiance of the Earth — the 'earthshine', as measured from a satellite — are dependent on many factors.

Fig 2.2.1: Overview of earthshine factors

Image: AT2-ELS

• The properties of the solar radiation reaching the Earth.
• Processes of absorption, scattering and reflection in the atmosphere.
• Processes of absorption, scattering and reflection at the surface.

The characteristics of any particular photon leaving the Earth could be the result of one interaction or of a number of successive interactions of the same or different types.

This section will look at each of these processes in depth.