Place it lower than the basic layer of the sand. Change after that the layer's Blending Mode on Soft Light.

Unreal Night Photo Effect

Merge down all the layers: Layer ? Merge Visible (shift+ctrl+e) and make a copy of the new obtained layer. Apply on this layer the next filter's option: Filter ? Render ? Lighting Effects.

Unreal Night Photo Effect

Blur out the layer (Gaussian Blur).

Unreal Night Photo Effect

After that, change the layer's type on Soft Light and minimize the Opacity till 40%.
   


Unreal Night Photo Effect

Insert now on a new layer the picture of the sky:

Unreal Night Photo Effect

Correct its sizes, selecting next option: Edit ? Free Transform (ctrl+t).

Unreal Night Photo Effect

Make use of the selection shown here: Filter ? Blur ? Radial Blur.

Unreal Night Photo Effect

Change the layer's type on Hard Light and increase the brightness of the layer (ctrl+m).

Unreal Night Photo Effect