Problem with lighting

Good day dear forum users. When I worked with the engine had a problem whose solution is not found because of lack of knowledge.

We have a sphere, with direct light, need to illuminate back side (dark side) without using emissive color and direct / point light
How I can do that? Emi * becomes brighter when viewed from, and additional light sources are not very good because I have lot of objects.
Sorry
bad English + google translate

It’s not clear what you’re trying to do. If you have a side in shadow and you want to add illumination then you need to add a light another light or you can place an object to bounce lighting onto that side (as you would with photography) though you don’t have as much control over how much illumination will come from bounce lighting.

problem
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This planet is dynamic object and you use some big movable point light as a sun source?

Oh, sorry.
Dynamic directional light?

anyway, in your case would be useful to add some ambient cubemap to post process settings.
maybe just a simple white texture