Stargate
At first Stargate was simply seen as an odd echo. The world is mainly the same as Homeline in the year 1560. The only really big change is that an unusually bright asteroid seems to have been captured by the Earth"s gravity. The red moon ( as the asteroid is called) seems to have been captured around the time of the
King Scorpion in Egypt .
There have been religious and cultural changes because of the second moon. And some changes that may be linked to the moon but the link can't be proved. (In this world Jesus has an Aunt Shani ( carmine-colored) who helps Mary and Jesus in Christian legend. Shani is almost as culturally important in Stargate's history as Mary.) Still the changes don't seem to add up to that much. The world was counted a weird parallel until the astronomers looked at the asteroid and then the original moon.
The Red Moon has clearly been artificially altered. There seem to be patches of red glass all over its surface. Meanwhile, the moon proper, called the White Moon on this parallel, has obvious artificial structures. They seem to be bases built by aliens.
The race is now on. Both Centrum and Homeline are doing what it takes to explore the Moon bases and the red moon!
Meanwhile, don't annoy the locals or get caught.