Where to begin..

The planet, along with the distant nebula, are both well done though the absence of an atmosphere does leave one to think that perhaps this earth has none? Either way, the lack of it actually cause's a slight issue with immersion.

A moon with an engine? Not a bad idea and well executed I might add, the trails that the engines make are also not that badly done though I am assuming that a part of the moon was used on earth - if that is the case, a bigger explosion would've undoubtedly taken place.

The only other critique I have is the lack of 'life' in the space scene, you have stars and you have a nebula which are good - but the addition of something happening in the distance (like perhaps a distant supernova or something along those lines, maybe even a meteor or comet or perhaps Earth making a last ditch effort to stop them *futile though I might add*) would add much to the scene.

Other than that, this is a great piece with some good talent. Keep it up!