Step 1. Making stars on the sky
Create a new document, fill background with color #000000. Go to Filter-> Noise -> Add Noise with options like this:
Amount : 17
Gausian
Monochromatic
Then go to Image -> Adjustments -> Levels set option:
Input Levels : 99 1.00 175
Step 2. Cut out 2 images below then put them into the background that you've done before. You can use Eraser to make images look smooth
It should now look like this
Step 3. Make bright border for the Earth:
Duplicate layer The Earth then set Screen for the new one.
Continue to do it again, you'll get this:
Step 4. Press Ctrl + click on the Earth layer to get selection, create a new layer under Earth layer then fill #FFFFFF
(Remember to keep selection when you create that new layer)
Move the circle to right a bit. Go to Filter -> Blur -> Gaussian Blur -> Radius = 95 Pixels
Step 5. Create a new layer then fill it with #000000. Put this one on top. Go to Filter -> Render -> Lens Flare
Change blend mode to screen for it, your result:
Step 6. Create a new layer and press Shift + Ctrl + Alt + E then press Shift + Ctrl + U to make it Black & White
Change blend mode to Overlay. Go to Filter -> Blur -> Radial Blur
Step 7. Create a new layer and apply this brush into your work:
Step 8. Adjust the color.
Go to Layer -> new Adjustment layer -> Hue / Saturation
Layer -> new Adjustment layer -> Channel Mixer
Layer -> new Adjustment layer -> Curves
Layer -> new Adjustment layer -> Levels
You'll get this:
Finally, you can add more planets on the top.
Here is my final result:
More Tutorials: 
