I agree with h0ughy.. almost all photos, astro and terrestrial, are manipulated in some way.
It's not "cheating", you're not introducing anything into the image that was not there in the first place. You're enhacing the detail you want to show.
The eye can handle a range in contrast and brightness very well, but the camera can not. Which is why earthshine pictures never have the same oomph that a naked eye view does.. but when those photos are manipulated, it looks much better.
Same as a terrestrial shot where some areas are in shadow and some are exposed correctly. To highlight the detail in the shadow, you need to play around with the levels or curves, and digital images always need sharpening.
Anyway that's my opinion and you're welcome to ignore it