Welcome to Wet Canvas! Leo
what a wonderfully colorful, creative piece!
The best place to post artwork for Critique is the Open Critique Forum
Here in the Creativity Forum we chat about all kinds of art related stuff and sometimes post images, but mostly its a discussion forum.
I will note about your piece, that the web site addresses on it really make it look like a poster rather than a painting, so when posting to the critique forum, please just post the art without the text as it is quite distracting. Also, we're allowed to post images sized 800 x 800 pixel maximum, so a slightly larger image would be great
I look forward to seeing this in OC forum, and others from you as i do very much enjoy these types of natural planet themes.
You can add a signature to your posts in the 'MyWC' section (see top left of your screen). This is a great place to put your website addresses. (see mine below, Peace - that's about as much space as a signature can take up).
Take your time, look around, there's so much here to see and learn, and again, Welcome!