Luna

thumb|249x249px|A photo of Luna taken in 2020 by NJSA's satellite, Endeavour.
Luna, often referred to as the Moon, is Terrania's only natural satellite. At about one-quarter the diameter of Terrania (comparable to the width of Commolacia), it is the fifth largest satellite in the Solar System, the largest satellite in the Solar System relative to its major planet, and larger than any known dwarf planet. Luna is a planetary-mass object that formed a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Terrania's (0.1654 g). Yeles' moon Demeter is the only satellite in the Solar System known to have a higher surface gravity and density.
Orbiting Terrania at an average distance of 384,400 km (238,900 mi), or about 30 times Terrania's diameter, its gravitational influence very slowly lengthens Terrania's day and is the main driver of Terrania's tides. Luna's orbit around Terrania has a sidereal period of 27.3 days. During each synodic period of 29.5 days, the amount of visible surface illuminated by Solia varies from none up to 100%, resulting in lunar phases that form the basis for the months of a lunar calendar. Luna is tidally locked to Terrania, which means that the length of a full rotation of Luna on its own axis causes its same side (the near side) to always face Terrania, and the somewhat longer lunar day is the same as the synodic period. That said, 59% of the total lunar surface can be seen from Terrania through shifts in perspective due to libration.
Category:Luna
Category:Moons
Category:Space
Category:Terrania
Category:Basic Cycloweb pages
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