This is a basic tutorial for Adobe Photoshop which will allow you to create an awesome planet-like object.

1 - Start a new document, must be squared size (400×400):

2 - Set background to Black:

3 - Now go to: Filters > Renders > Lens Flare and use the following options and values:

4 - After that, go to: Filters > Stylise > Wind and mark the Wind option “From the Right”:

5 - Repeat step #4 but instead of using the “From the Right”, use the “From the Left”:

6 - Now go to: Edit > Transform > rotate 90ºCW, and repeat steps 4 and 5 :

7 - Go once again to: Edit > Transform > rotate 90ºCW so the image go to the first position.

8 - To finish up… Go to: Filters > Distort > Polar Coordinates, Rectangular to polar, with the following values:

9 - You image should look like the one above. Lets turn it sideways, for that go to: Edit > Transform > Rotate 90ºCW, so it starts looking more like the image below:

10 - Alright, now, if you wish to color it up, hit CTRL+U.
After that, just use your imagination.