Press Alt button and make a mouse click between the planet’s layers and the brush’s layer for the darkening to be applied in the limits of the planet.

 



Combine in a group all the layers composing the big planet and its darkening (hold on Ctrl button to mark out the appropriate layers and then hold on the left mouse’s button while taking down the marked layers on Create a new group selection). Make a copy of this group, press again Ctrl button, mark out both layers of the planet on the copied group, press on Ctrl+E, combining these two layers into one. The Free Transform option may help us to turn over the copy and place it the way it is represented below.



Apply the next parameters for the copy: Fill 20%



Find in Internet now a picture of the sky.



Insert it on our basic picture.



Make a click on the lowest part of the layers’ panel on Add a Mask option. Select the Brush Tool (B) of black color and try to clean out that part of the sky situated on the bottom and on the top.



Find in Internet a picture of Mars planet and downloaded it out.



Cut out the planet itself and introduce it on our picture.



Apply the same method and the same operation we did with the big planet. We have to dark out the planet the same way we did before.



Make a copy of the planet and turn it over for getting its reflection.



The layer in reflection should have the next parameters: Fill 20%