Here is a image I created while on holiday. I used Blender to render the planet and then composted it together in Photoshop
I’m asking for honest criticism, anything you feel can be improved, please post it so I can improve 
Hi mikh3x4! This is a cool concept for you to take on! It looks like a good start. How did you create the chunks of the planet breaking apart; was it rendered that way or did you use masks in PS?
Now, I can’t say I have ever seen a planet exploding in real life (yet), but I will try to suggest some ideas to help you improve. Take any that you like!
To start with, if you would like real 3d chunks, I would suggest beginning with a sphere and using the fracture plugin to break it up. There is a great, easy to follow tutorial on Blender Cookie on how to use this tool in a controlled manner. Then, once you have your planet in many seperate pieces, you can adjust the surface chunks to show them being blown out in whatever orientation you wish. I would try to make some areas more stable than others, rather than a uniform explosion outward. To keep your molten center when you use the explode modifier, simply cut out the space that the hot core will be occupying in the planet/dirt from the sphere before you fracture it. The simplest way is to create a sphere for the magma as well, duplicate it, then join this duplicate with the planet/dirt sphere you wish to fracture. Lastly, flip the normals on this tiny interior sphere. This will you give a hollow interior when you fracture the larger sphere.
One tip- Before you fracture any object, scale it up as large as you can. I usually scale them all the way up to the edges of the work grid, for good measure. This will make the edges that get fractured more accurate.
Besides that, I would suggest giving the planet a little different lighting. Use a sunlight to light the scene, and angle it so that only part of the planet gets light. The other half could be in almost complete darkness. If the magma is giving off light, then it will light up the areas between cracks and show up more in this dark area. This would give a more dramatic look, I feel.
You can try adjusting the size property of the sunlight in it’s options panel to soften or harden the shadows, whatever looks good to your eye.
Hopefully some of these ideas may be of help to you. I like your concept a lot, keep going with it if you’ve got time!
Yeah, I did the chunks in Photoshop. Thanks for all the sugestions, I’ve never used the fracture plugin but there must be a first time. I’m onto remodelIng it using the plugin. Thanks again