'Verse - Eternity - Arca (moon)

Encylopaea Ole'yos
World Name: Arca 
World Type: Moon
World Sub-type: Artificial/Sanctuary World
Parent planet: Ulor'in (Gas Giant)
Solar system: Ole'yos
Circumference: 40233.6 KM
Home to millions of animal species, including several sapient species. Arca was not a natural moon for Ulor'in and was placed in orbit of the Gas Giant about 4 billion years before the Age of Humes. The unique physical property of the moon was not fully realized until the proliferation of scientific space probes sent into space. 
While Ulor'yn orbits its star, Ole'yos in 1024 days, the moon rotates 64 times every 365 days of Ulor'yn's orbit. The orbit is elongated, bringing each winter season, Arca experiences 4 days of darkness and a month-long Summer that burns away forests. 
The moon is artificial, constructed in a thick shell in the shape of a torus that encircles a collapsed neutron mass.