Hey fish, nice too see some enviros! I think the problem with the top one is that the mid ground has more contrasty values then the foreground. Foreground should always have the highest values in the painting as they are closer to us and don't get de saturated by atmosphere. Otherwise interesting idea.
Second one is better but it's fairly early on for me to see much. Just make sure you don't forget about foreground in it. Also with those hovering black things - make sure you scale them down and repeat them in the background. That can be a really powerful prop to show perspective and the expanse of the enviro.