I started this poster, advertising my work, by creating a blank black layer in photoshop. I then added noise to give it the star effect. After playing with the "brightness/contrast" and "levels" this stage of my star field was complete.
My next step was to create a glow around the stars, making them look more like nebulas. To do this I duplicated my star layer and filtered this new layer with a "gaussian blur." I then changed the mode of my star layer to "linear dodge." I altered the colour balance, and gave it a blue hue.
Next, I added in a couple brighter stars and the sun. To do this, I created a new layer and set the mode to "screen." I then rendered a couple "lens flares" altering the brightness of each one.
To finish it off, I added in the earth, altering different effects to make it look as realistic as possible. I also added in text with a radiant to make it fade into darkness with the earth.