Earh Ablaze

This one's a long tutorial but its easy and results are guaranteed. Makes a molten planet…

Step 1: Create a new document: 800x800, white background. Then, create a new layer (Ctrl+J)

Step 2: Take your Elliptical Marquee Tool. While holding down shift, create a circle almost the size of your document.

Step 3: Fill the circle with black (Shift + F5).

Step 4: Then go to Filter > Render > Difference Clouds. Then Press Ctrl+F three to four more times to reapply the filter.

Step 5: Go to Image > Adjustments > Levels and follow up on the settings shown (somewhat).

Step 6: Then go to Filter > Sharpen > Unsharp Mask and give the settings of:

Amount: 475%
Radius: 3
Threshold: 14

Step 7: Then apply the Spherize filter (Filter > Distort > Sherrie) with an amount of 100% and then again with an amount of 50%.

Step 8: Open up your Color Balance dialog box by pressing Ctrl+B or Image > Adjustments > Color Balance. Give the following settings for each of the items:
Apply the following color levels:

Shadows: [+100] [0] [-100]
Midtones: [+100] [0] [-100]
Highlights: [+70] [0] [-15]

Step 9: Use the Unsharp Mask Filter again only this time set the amount to about 300% and Threshold to 15. (Filter > Sharpen > Unsharp Mask)

Step 10: Now create a new document of a size 1024x768. Fill it with Black.

Step 11: Go to Filter > Noise > Add Noise. Give the following Settings:

Amount: 4.9 (More amount means more stars)
Distribution: Gaussian
Monochromatic: Checked.

Step 12: Duplicate the Layer and set the Blending mode to Overlay.

Step 13: Select your Background Layer again and go to Image > Adjustments > Brightness/Contrast. Increase your contrast so that the stars are visible.

Step 14: Now, go back to the burning planet document. Ctrl+Click on Layer 1 to select the planet and then Ctrl+C to copy it to clipboard.

Step 15: Switch to the stars window and paste the planet there. Make sure the planet is on top of the other two layers.

Step 16: Apply the following Blending Options (Layer > Layer Style > Blending Options).

Step 17: If you find the edges of the planet a big jagged, use the Blur Tool (R) to blur out the edges.

Here is my Final:

Click to enlarge