Enorme Nave de Mando Alienígena Sobre un Planeta Azul Asediado

A gigantic alien command ship in orbit over a blue planet supervising a full scale invasion. The command ship is colossal, sleek and deadly with weapons and sensors all around. There seems to be an off white colored organic exoskeleton type indestructable armor fitted to the massive ship with a smoothly integrated evil looking alien skull into the front of the gigantic dreadnaught. Done in a fantastic detailed science fiction space opera style