Solunsa

Solunsa is a fictional terrestrial planet created for worldbuilding and science fiction. It is commonly placed in the Trionis system, a sun-like star located several dozen light-years from Earth. The name combines solar and lunar roots often used in speculative settings.

Solunsa orbits its star in the temperate zone with a orbital period of about 320 days and a semi-major axis near 0.95 astronomical units. It has a radius close to Earth's and a similar mass, producing moderate gravity. The atmosphere is predominantly nitrogen and oxygen, with surface pressure near 1.0 atm.

Surface geography features two major landmasses separated by shallow seas, plus archipelagos and varied highlands. The average surface temperature sits in the mid-teens Celsius, yielding a climate with distinct seasons. A global magnetic field provides modest shielding from solar wind.

In many depictions, Solunsa hosts a diverse biosphere, including temperate forests, grasslands, and coastal ecosystems. Some stories introduce intelligent inhabitants or human/alien colonists, while others focus on exploration, climate dynamics, and resource management in a frontier environment.

As a fictional setting, Solunsa is used to explore themes such as terraforming, diplomacy, and ecological balance. Its flexible parameters allow worldbuilders to adjust geology, climate, and biology to suit different narratives without referring to a real-location exemplar.