A map of a popular theory of the universe's structure known as the Illos Geode. It speculates that the two moons orbit Safira, with a ring of light, a ring of dark, and a "Scab" of mountains encasing the solar system. The brightest point in the light ring is the "Soul", appearing in the sky as the sun.
Because the planet's inhabitants don't know enough about astronomy, the solar system where the planet of Safira resides is without a name. The nearest neighbors of Safira are its two moons, Saros and Cosmos, and further beyond, it's the Glaatus asteroid belt. Meanwhile, a yellow sun shines roughly 92 million miles (150 million km) away.
The make of Safira is extremely similar to that of Earth's (saltwater outweighs freshwater 19:20, and the atmosphere is made up primarily of nitrogen, then oxygen), but the amount of water is where you truly see the difference.
71% of Earth's surface is impressively covered in water, but it's instantly dwarfed by Safira's 85% water coverage. Add on the planet's twin moons, and you'll quickly see why aquatic adaptations are king. But all this water means that Safira reflects a large portion of sunlight, so the planet's overall climate is slightly colder than Earth's.
Meanwhile, the night skies shine differently than Earth's. Quite literally. The two nearby moons cause the nights to be much brighter, and the closeby Glaatus asteroid belt means that meteors frequently fall onto the planet, and shooting stars are commonly seen.
And yet, Safiran sciences are extremely primitive. The planet’s inhabitants know very little about the world around them. What they do know (whether or not said knowledge is accurate) is derived from myths or observation of what is visible with the naked eye. As with many societies, new scientific theories are seen as outlandish and impossible, holding back the planet's development.