you're going to need to give more information. specifically, what it is you are trying to do and how you are trying to achieve it.
the glare node only works on objects emitting light, and nothing seems to be emitting light in your scene. therefore it won't have much of an effect.
your rgb curves and blur node is set up in a way such that your rgb curves node darkens the image considerably, and then only the lightest parts of that image are blurred. to see what i'm talking about, plug your rgb curves node into your viewer node. everything that you can see in your backdrop is what becomes blurry. so you might want to change the rgb curves node so that it doesn't darken the image as much or remove it completely, depending on how apparent you want the glow to be.
if after all that, you still see no change, go to your render settings under post processing and make sure the compositing box is checked.
as for the backdrop, i'm assuming you're referring to that giant plane behind the meteroid. unfortunately i can't help you with that since i can't see how you have the material and texture for it set up. all i can tell you is to make sure the object isn't restricted from rendering in your outliner.