An image of Selene
Star Sol
Type Barren moon
Primary Gaea
Gravity 0.16 G
Orbital distance 1.0 AU
Day length 28 days
Year length 28 days
Diameter 3,474.8 kilometers
Axial tilt 1.54°
Mean 220 K
Minimum 100 K
Maximum 390 K
Atmosphere composition Trace argon, helium, sodium and hydrogen
Surface pressure Negligible
Faction Eteno Imperial Triumvirate
Population <1,000 commuters
Major imports food, machinery
Major exports helium-3

Selene (sometimes known as the Moon) is the moon of Gaea. It is tidally locked to its planet, and has almost no atmosphere.


The English name for Selene is simply known as "the Moon". Since the advent of space exploration, the name Selene was given to it, derived from the Ancient Greek word for moon.

Physical characteristicsEdit

Selene is a rather large satellite for a planet, having 27% the diameter and 60% the density of its primary. Thought to have formed 4.5 billion years ago, it is said that Selene was formed when an object the size of Mars collided with Gaea, sending debris into space forming a ring system. The ring system eventually coalesced into the moon.


For thousands of years, humans have used Selene as the basis for their calendar. One revolution by the moon is equivalent to one month by the Gregorian calendar.

In 1969, Human astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on a celestial body other than Gaea. This officially marked the moment humanity had entered the early space faring age.

During the War on Gaea, Selene was used as a military supply base, originally owned by the Buyuk Empire, but later captured by Eteno forces. Selene has since become a quiet backwater and producer of helium-3