I found more about the Three Kingdom Wars at Wikipedia:
And this passage about the incident reported in Wonders:
Many stories have reported martian encounters within the Wu kingdom. Evidence is identified in a story by Eastern Jin writer Gan Bao. The story is part of Gan Bao's writing called In Search of the Supernatural.The story states within the Wu kingdom, the ancients recorded an event where playing children encountered a child with a strange appearance who stood at 1.3 meters tall, was dressed in blue and possessed shining eyes. Since the children have never seen this creature in the past, they surrounded it and asked it many questions. It replied, "I am not from the earth, but from the Mars, I saw that you are playing so happily so I came down to see you." The being also said, "The state of having three kingdoms standing will not last long, In the future, the world will belong to the Sima family.The children, became frightened and reported this to the nearby adults. However, when the adults came to the sight, the strange being disappeared by shrinking and jumping into the air. When people lifted their heads upward to watch him, they could only happen to see a white silk cloth dragging along a long belt, flying fast towards the sky above. The event was so bizarre, nobody would … speak of the event again
I've emboldened "Many stories have reported martian encounters within the Wu kingdom" because it would be interesting to see those stories.
But also intriguing is the stipulation that the "child" says he came from Mars, and this from an account written in (circa) 260.
What would allow a writer of ancient times to zero in on Mars as the site from which an wondrous visitor would show up on Earth?
(Yes, Mars, because it was red in the night sky, invited humans to give it inordinate attention, as was the case with the Greeks and its God, Ares, or for the Romans, its God, Mars.)
Was Mars, once a place, with canals and civilization, that was decimated by a cosmological disaster or a cataclysmic internecine war or even a termination by something outside of itself, and in the not too distant past?
Wonders in the Sky indeed, and here on Earth also.