Mars (also known as the Red Planet or Sol Secundus) was once a cool D-Class world but was terraformed into a temperate E-Class world. It is the most Earthlike world in the Sol System aside from Earth. It has a rotation period of 24 hours, and an orbital period of 687 days.
The first humans to step foot on Mars did so on March 23, 2024 near Valles Marineris. After four missions, the last one leaving Mars on July 4, 2039, Earth sent out reusable rockets full of compressed chlorofluorocarbons to Mars. Their payload was launched into the Martian atmosphere and crashed onto the surface. This caused the compressed gasses to be ejected into the atmosphere. For a decade, the rockets kept bombarding the surface with massive containers of CFCs. This caused a global change in the temperature.
As technology improved, driver probes were sent to the asteroid belt and diverted many ice asteroids into the Martian orbit and skimming them across the Martian atmosphere.
While diverting asteroids, one probe accidentally discovered an iron rich dwarf planet. Scientists on Earth debated moving this world into Martian orbit to keep future inhabitants of the terraformed world safe from solar radiation. After years of debate and invention this was accomplished. The new moon was given the name Simud. Mars was completely terraformed by 2475.
Mars has a population of just over 10 billion people spread across the cool tundras, forests, deserts, and cities of Mars. Thanks to the low gravity, Martians are taller and weaker than terrestrial humans.
Mars is the second oldest human colonized world and second most diverse culturally as nearly every country sent colonists to Mars, even religious groups that lived in the higher elevations moved and built monasteries and temples in the now snow covered higher elevations.
Many groups who’d grown up near the Mediterranean moved to the new Hellas Sea where they set up many small fishing cities.
The fourth planet from Sol, Mars has an atmospheric pressure of one atmospheres and a mean temperature of 6,3°C (43.4°F). Due to its distance from the sun however, most of the climates are cooler than their Earth counterparts. The four major volcanos on the planet jut out of the atmosphere entirely. Many of the major cities on Mars exist in some of the larger craters near the local atmospheric datum. Each city has their own local weather. Note that before terraforming, Mars had a much lower pressure and average temperature.
At higher elevations, the terrain resembles terrestrial alpine biomes and the Hellas Sea resembled the Mediterranean Sea. The poles are larger than their earth counterparts and the winds on the planet are much more predictable than their Earth counterparts.