hmmm, not sure if the photos from NASA are according to the rules. did you get permission from NASA? also, as far as i remember. unless rules were changed. no premium images and such, can be used. i could be wrong on that 2nd one.

NASA images are .gov, so they are considered public domain, I believe...
From the NASA website:
"NASA still images; audio files; video; and computer files used in the rendition of 3-dimensional models, such as texture maps and polygon data in any format, generally are not copyrighted. You may use NASA imagery, video, audio, and data files used for the rendition of 3-dimensional models for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages. This general permission extends to personal Web pages.

This general permission does not extend to use of the NASA insignia logo (the blue "meatball" insignia), the retired NASA logotype (the red "worm" logo) and the NASA seal. These images may not be used by persons who are not NASA employees or on products (including Web pages) that are not NASA-sponsored.

NASA should be acknowledged as the source of the material except in cases of advertising. See NASA Advertising Guidelines."

But I agree, that a "premier" tutorial that can't be publicly seen shouldn't be allowed...Just like tutorials in a book can't be used, because those without the book can't see the tutorial...

Without the tutorial to compare to, it looks like your exploding moon is wonky.

"Find any tutorial on the internet and follow it (and possibly give it your own interpretation). Don't forget to mention the tutorial you interpreted."
NASA has been credited. See my description I posted the link to the tutorial. You may not have total access to the detailed tutorial, however you can plainly see the jest of it. MossyB, you are certainly entitled to your opinion about my moon, mighty strange remark considering you also have an entry in this contest....

That Image of the Day on the NASA site has been a bookmark of mine for a long time, Dragoncide, those images ARE ok to use on this site, or for non-commercial purposes, as MossyB states. As far as this particular tut, yes, it's frustrating if you're not a member, but the images and video that they DO show should be enough for an artist to come up with something like they show. Author, you've done a very commendable job here, looks good to me! SBS is well done also.

nicely done

i wasnt sure about the image being legal or not. thanks for the clarification everyone. it is a fantastic image. and still i must say is very unfair for everyone else who wish's to learn how to do such a thing. but as the rules do say yes your results are very on par.

Dragoncide, I do understand what you are saying. You too can become a premium member, there is lots of cool stuff there.

will you buy me a premium membership? =D

The tutorial had a highlighted simple planet to make contrast with the dark moon, and a saturated sky (meaning very blue, even if space is black) to make contrast with the gray exploding moon.
Even if this was not explained in the tutorial ( i can only guess, i don't know) - these tricks create the point of interest, the equilibrium of the image, so that the exploded moon really stands up.
In many tuts the authors don't explain this stuff, either cause they think it's obvious and well known, either cause it's in their blood and don't realize when they're doing it. But you should pay attention to these details - you can't really learn skills from others, but you can steal them ..

whatever...

Just trying to help, not to criticize or anything, it's a good attempt.