Solved via Mr Zak solution:

I'd try to apply scale for the moon object (object mode > ctrl+a), then in edit mode recalculate normals. It looks to be the reason for difference in shading in viewport

Solved via Mr Zak solution:

I'd try to apply scale for the moon object (object mode > ctrl+a), then in edit mode recalculate normals. It looks to be the reason for difference in shading in viewport

WHAT DONE:

Changed Scale

Recalculated normals