Step 1:

Let's start out by creating a new file. I used a 530x795 pixels canvas which is the same size of the stock photo used in this tutorial. Now grab the image below and insert into your canvas.

Step 2:

Duplicate your Stock Photo layer. Then go to Filter > Blur > Gaussian Blur and apply the settings below.

Step 3:

Then under Layer Style(Layer > Layer Style) add a Pattern Overlay blending option to the blurred layer.

Step 4:

On the layers palette move the original Stock Photo layer above all layers so it shows up on your canvas. Then set the layer's blending mode to Hard Light.

Results:

Alien Particles Photo Effect.