The Solar System. We live on the third planet in it, called Earth, and we know there are seven other planets. However, people didn't always know that. The number of objects considered planets has changed multiple times. In ancient times, people were only aware of a few planets, sometimes called "wandering stars", but our knowledge has expanded as time has gone on. Before we reached our current model of eight planets and numerous dwarf planets, many hypothetical planets were theorized, although they were eventually proven false. But what if those hypothetical planets did exist? What if we had more planets in different locations? What if we looked up at the night sky and saw a Sea of Stars?
This Solar System has sixteen planets orbiting the sun. The names are derived from the Roman pantheon of gods, although other cultures have different names for them. The italicized names are the names given to the planets by the Martian peoples, who named the planets for the kings of old. Humans originally only knew of the planets from Mercury to Saturn. Caelus was discovered in more recent times, followed by Vulcan, Bacchus, and Neptune. Pluto and Janus were both discovered within the last 100 years and exploration of them is ongoing. Martians knew of all of the first 12 planets except Vulcan, due to their closer proximity to the outer planets. The others were discovered later on, although they did not learn of Pluto and Janus until after contact with the humans of Earth.
Earth is the home of the human race and all associated lifeforms. It is different from our planet because it has more landmasses, such as the continents of Hyperborea and Zealandia, as well as an enlarged Antarctica (Australia). For the sake of convenience, humans exist in this timeline and history remained relatively the same until the last 3000 years.
Technology and Discovery
Technology has progressed much faster in this timeline. Our 2016 level of technology was achieved in the early 20th century. The Romans started building the first steam railways in the 1400s. The car was invented in the early 1800s, followed a few years later by the plane. Space travel was achieved in the mid 1800s. Thanks to increased east-west connections, technologies like the printing press and the firearm progressed faster. Industrialization began in the late 17th century. Discovery has also moved much faster, with Atlantis being discovered in 947 and Vesperia (North America) first being explored by the Norse in the 1130s and eventually by the Romans in the 1200s. The Mongol Chinese discovered the Pacific continent in the same time period, eventally reaching the western coast of Vesperia in the 1320s. The Africans began exploring Amazonia (South America) in the 1300s as well, eventually being joined by the Europeans. The Arabs began colonizing Kerguelen in the mid 13th century and eventually moving from there to Australia. The Europeans did not begin colonizing Australia until the late 14th century. All of the world had been discovered by the mid to late 1600s.
Due to the continued existence of Roman paganism, Christianity did not become very major. The roots of Christianity changed as Jesus was not executed on the cross. Instead, he led a massive migration of his followers east, first to Roman Parthia, where they were hosted by Alexander II before being forced to move again, eventually settling in Bactria. Jesus converted large numbers of people there to his religion before deposing the existing Bactrian government and replacing it with his theocracy. Today, Bactria is the center of all ATL Christianity and is ruled by a direct descendant of Jesus through his eldest son. The King of Bactria is equated with the leader of all Christendom. Jesus' religion also spread to Turkestan, Scythia, parts of India, and China, and eventually made its way into Europe, taking hold in parts of Germania, Francia, and Britannia. The Christians in these nations were driven out to the colonies in Vesperia, creating a strong Christian presence in modern Vesperia. Germania and Britannia maintain Norse paganism as their main religion, while Hibernia and Alba continue to practice Roman paganism. After the pagan religions, the largest religion in the world is Islam. It developed in the same fashion, but the Muslims didn't expand as fast as they did in real life due to major opposition from the Romans. Islam spread south and east to India, Kerguelen, and Africa, and eventually north to Rus' and surrounding areas. During the Mongols conquests, Islam was heavily repressed, but many Mongol khanates slowly adopted Islam before it spread back into Mongolia and China, eventually becoming the religion of the Great Khan himself. However, Islam was never able to replace the strong footholds that Christianity had in Bactria and Persia.
Mars is a planet full of life in this timeline. The local species call it Numrar, derived from Num (the land mother) and Rar (the sea father). Mars is approximately half land and half sea, with most of the land being concentrated in the southern hemisphere. Mars made contact with Earth before Earth made contact with Mars. The Martians landed in Hyperborea in 1916 AD. The humans landed on Mars four years later. Mars has three moons.