print design - Creating a molecular cloud in Photoshop

I'm currently teaching myself design and have been asked to create a molecular cloud similar to that in the attached image. I'm seeking advice on how one might obtain a similar result/effect in Photoshop. Thanks in advance.

Answer

It is fairly simple. Here are some key points:

STEP 1 - I first drew a random 1px line with the pentool.

STEP 2 - I used mask and brush tool + soft round brush to fade parts of it slightly.

STEP 3 - Then I drew bunch of dots in every corner. They vary in size.

STEP 4 - Then I made a brush out of it.

STEP 5 - Adjusted the brush settings

STEP 58 - Now if you use ellipse tool to make a path and use stroke path + brush tool, you get something like this:

You will want to stroke path multiple times with different brush sizes. Of course for realzies, you'd want to use more than one brush.

STEP 380 - ...and after inverting colors, adding bunch of highlights, duplicating the brush pattern multiple times, using different blend modes and using filters > blur > tilt-shift to blur some of it... this is what you get: