That looks just as I would expect. I can't remember exactly what gear you have but I looking at the image I would say it looks typical of a DSLR and lens combo of entry to mid level.
I get the same problem with my gear. My sensor is pretty good (a 24mp modern design) but my £250 70-210 just does not have the resolution.
I am just waiting for my lottery win
Edit: Forgot to say - If you want more sharpness, shooting when the moon is high in the sky can give better results as you will be shooting less distance through the atmosphere. That said it won't be a whole lot better than what you got last night but maybe a little.