Firstly, I am glad to see another piece from you Tobias. Now to begin a critique, I should like to emphasise my broad message about the piece. Simplicity is always a good ideal, but I feel like this piece does not reach your potential. Not to say that it needs to be more complicated. Rather, I think it could be further crafted with your abilities. There are some clever ideas in this piece in any case, though. You may be aware of all this, but as you have critiques enabled, I take it you won't be unhappy with some (hopefully) helpful feedback. I shall address the following in sequence: (1) vision, (2) originality, (3) technique. Impact in my mind is a product of all of the aforementioned issues (vision, originality, technique).
Concerning vision, which I'll interpret to be how you've given compositional form to an idea, there are positives and negatives. The variation on the 'red, green and blue' colour scheme is alright, but not totally convincing. I can see that the blue flare mimics the planetary blue atmosphere and the far off nebula, while the green and red-orange seem to indicate the 'dark-sides' of the planet and moon respectively. Other than eye-appeal, I find only the blue compositionally interesting since it moves from foreground to background (from the flare to the nebulae). The other colours feel disconnected with any greater compositional form. Maybe if the green replaced the red-orange or vice-versa, there would be greater unity in idea? That is, a single colour would then be representing back-lighting of the moon and planet. Additionally, you could add a third instance of this colour. We have three instances of the blue colour: nebulae, planetary atmosphere, flare. So, for example, you could have orange-red aurorae, orange-red back-lighting to the moon, and perhaps a lava flow. That would be far more compositionally interesting. Then again the orange-red is already used to highlight cities in this piece, it could be argued. So we could have the lava-flow and the city-lights to balance the piece: 3 instances of blue, 2 of orange-red and 1 of green. That might work, but I feel like the green colour would be too lonely, being a mere place-holder choice. So I'd lean towards the former suggestion of 3 blue and 3 green or orange-red coloured components of the composition. Now concerning a different part of the visionary composition, we have two planets and a moon, or a planet and two moons. It seems to me that the moon (foreground) and some planet is fine here, but the other planet (whichever one doesn't seem to matter) doesn't do much in the composition. In other words, it seems like a stock-standard space art choice to throw in another planet. Doing something interesting with the extra planet/moon, or dropping it completely, would seem wiser, then. On the topic of excess objects, I am not seeing the point of the gate on the foreground moon. Again it seems like mere instant eye-appeal. I can see a suggestion of perhaps, an entrance into the city-worlds of the planet. But that idea isn't emphasised enough I think. Maybe some other feature could enhance that idea if you wanted that. For example, a massive city centre just behind that gate. Problem would be whether this unbalances the piece or not. Another criticism is to be made about the star-field: it seems haplessly distributed. More selective use, perhaps at the expense of 'realism', could make for a stronger art-work.
In terms of originality, quite a few pieces have a foreground moon, an astronaut, flares, aurorae, planets (indeed the one-too-many planet). I don't readily recall this orientation of foreground moon arching towards the viewer with a gate, so that's a plus. Otherwise I don't see anything original here. Actually, working on the vision as suggested before, would boost the originality already.
As to the technique, I also think it has some clear issues, though it's not all bad. The moon terrain in general is convincing, though some parts seem rather sloppy. The gate for example, seems to have been erased with a hard edge, far too artificially. Especially unconvincing to the right. Likewise for the nebulae to the far left, there appears to be some harsh cut-off between the coloured zones. I think a little more nuance in these light-dark, green-blue cut-off areas of the nebulae would help it excel. The use of colour in this piece, on the other hand, is good. The reflection of the green aurorae on the two planets (so I will call them) is well done. The faint orange-red and blue reflected on the foreground moon is nice too, including its apparently different manner of reflecting due to its different material composition. Nicely done. The planetary texture are alright, though nothing stands out in particular (this criticism could partly be filed under vision). The star-field is fine though again with vision, I think it doesn't stand out; it's somewhat bland in how it is distributed. I am also unsure about the perspective of the astronaut, though the flare is fine, I wonder whether it could be more obviously affecting the scenery. Perhaps if it more clearly reflected on the surroundings, rather than giving off a faint glow, it would be more convincing. A final criticism on technique concerns the right part of the main planet's atmosphere-to-texture-map zone. There seems to be some jagged compression of some sort, which looks bad.
Wrapping up, I'm glad you've made another piece and look forward to more. On the other hand I would be delighted if, as I know you can, you crafted your future pieces more carefully. A bit more attention to technique, but more importantly to vision, is required. Originality will improve with better vision already, but I think vision comes first since a good piece is better than an original yet bad piece. Once you've got things on the right track, branching out into new approaches to scenes will bring about greater originality.
Beautifully done. I rate it 3.5-3.75 stars. 2.5 stars is OK 3 stars or above is Good 2 stars or below would be considered far from finished.
I admire the panorama view of that rocky wall on our right hand side as it swoops towards the left. This wall creates a sense of perspective, something I do not usually see in most photo manipulations of nature. This one point perspective technique you used for the wall of rocks with the arch draws the viewers eye towards the duo habitable worlds.
The northern lights are quite beautifully placed over the world which gives the viewer a sense of tranquility. (it must of been quite exciting to be a citizen on such a world, you see a blue marble and a baron moon with some auroras). The city lights are quite beautiful and adds a sense of depth on the surface of the planet or moon.
Some advice to improve: the clouds on the planet could use significantly more detail to add some more depth in the pictures. The rocky wall although from a distance looks quite beautiful too could use some more details up close. Overall great work.