The sky looks fake in a way... The lighting looks to intense on the building for it to be night time. It looks like its just a cooling filter in the day light...
If the sky is fake, which it looks, I would lose the comet. It's kind of pushing your luck lol. Without the comet, you may have to take a 2nd gander to decide, but it looks way fake with the comet.
As for the cooling effect on the structure, I think it works and I really like it. Framed well too.
Jezus, do you know photoshop? I took the photo during daylight (Pentax K100D and Sigma 18-200mm lens) Then B/W convertion. Added bluetone. Replaced the sky. etc etc.
This picture is a result fm photography and photoshop.
Hope you like it.