The super battleship aliens are here. Why don't the five ships come anymore?

Those five spaceships from aliens are more like death squads, because the other side is not sure whether their technology is above the earth, so they send an advance team for reconnaissance. If we can prove that we are stronger than the earth people, I'm afraid people on planet G will immigrate to the earth. However, their communication was destroyed when they came, and the idea of sending a model similar to Planet G through the lighthouse was terminated, so that the commander of Planet G would think that their advance team was completely annihilated on the earth. Presumably, the technology of the earth people was better than theirs, so they would not send a spaceship to take risks again ~ so there would be no follow-up troops. The missiles of modern destroyers are aimed by fire control radar or visual control radar. Enemy ships can't be shown on the radar at all. At first, they were all disturbed and had to rely on naval guns. . . In fact, the target of sinking the enemy ship in the later period is the buoy at sea, which is why the last respondent said that he didn't launch the "island bomb" at first. . .