The diffrence in time
Looking outside the ship's windows, Quinn could tell that the Earth that he once knew looked quite different from before. Back then, few satellites surrounded the Earth. Later, most of them were destroyed by the Dalki in order to sabotage the humans in the war.
This situation forced humans to create and rely on different technologies if another threat like the Dalki might appear. After a thousand years since the Great War, Earth now has many layers of defences. For one, there were fleets of ships that would just encircle the Earth.
The spaceships were in different colours and flew just to specific zones. One such group of spaceships had a green tint on them. They also clearly had several other weapons on board and were equipped with mechs. It didn't take much to speculate that the Green family owned this fleet.