for the lighting on the planets, I thought of making the planet on the right look close to the screen and look far away for the planet on the left. At the time of determining the lighting, I imagined the light source to be from the north on the right, so the light hit the planet on the left from its right side and for the right planet I made the back dark because in my view the camera was behind the planet. I can't explain the position of the planet in words. But thanks for the feedback, I appreciate it .UzU.

You're right, I didn't think about that when I made it. I just wanted to add something other than stars, so I thought why not add something like stars passing by.