Why does my bumped diffuse material get lit in a weird way?

This is what it looks like with the material of earth being only diffuse.

This is what it looks like with the material of earth being bumped diffuse.

As you can see, the clouds are still lit but the ground is not.
Moving the light source (point light as it needs to simulate a sun) around shows that parts that should not be lit are actually lit sometimes. It’s very inconsistent.
You can actually see that a small part on the back of the planet is being lit in the scene view.

Removing the clouds does not change the weird lighting so I suspect there is something wrong with my bumped map.

This is my bumped map, that Unity for some reason converts to a blue mess.

How can I have this planet have some bumpiness, without having screwed up lighting.

I solved the problem, the bumpmap file I had was simply too big in resolution.
After scaling the image down in Photoshop, Unity was capable of making a functioning normalmap.