Photoshop --> Layer Styles --> Stroke --> Mode: Gradient Burst. Takes about 2 minutes if you have the basic shape and all those shadowy crevices and overlaps will form almost naturally. Of course you can mimic the behavior with blends just as well....
Take a close look at that pattern. You will find that it is made up of only two shapes. They are then duplicated and enlarged a few times until the two shapes look like they had merged with each other.
That was the first layer, the second layer consist of a radial gradient.
And well I believe that is about it.
Good luck... Oh BTW if you plan on doing this for anything other than a learning experience, change the shapes to your own. Making an exact copy is a copyright infringement.
When constructing this, orient yourself by the light line pattern, not the dark one. Start with a shape like an "open 8". Then use offset Path to create the inner shapes.