SunMoonEarth

SunMoonEarth is a term used to describe the Sun–Moon–Earth system, emphasizing the interconnected motions and interactions of these three celestial bodies. In astronomy and space science, it refers to the gravitationally driven relationships that shape orbits, lighting, and tides.

The Sun is the dominant mass in the system; Earth orbits the Sun with a year of about 365.25 days; the Moon orbits Earth with a sidereal period of about 27.32 days and a synodic period of about 29.53 days. The Moon’s orbital plane is inclined about 5 degrees to the ecliptic, which means eclipses occur only during specific alignments of Sun, Moon, and Earth.

Key phenomena associated with the Sun–Moon–Earth system include eclipses (solar and lunar) that occur during syzygy, the straight-line configuration of the three bodies; the lunar phases produced by changing geometry of the Sun’s illumination of the Moon; and tides caused by differential gravitational forces. The Sun’s light and gravity also drive seasonal and climatic effects on Earth, though these are influenced by many factors beyond the Moon.

In educational and popular contexts, SunMoonEarth is used to illustrate three-body dynamics, orbital geometry, and the relationship between illumination, orbit, and timekeeping. In media or software, it may appear as a project name or interactive model that simulates the geometry and motion of the Sun, Moon, and Earth.