The celestial sphere is a conceptual tool used by astronomers to locate stars without having to account for distance. The celestial sphere is akin to the following: imagine the Earth in the center of a hollow sphere and the night sky was the mural that decorated the inside of the sphere. In order to locate objects on the celestial sphere, we use the equatorial coordinate system. If the celestial sphere were a map, right ascension would be longitude and declination would be latitude. Regarding its proper context, right ascension is the measure eastward, in terms of sidereal hours, from the vernal equinox a celestial object is. As such, a star slightly east, past the vernal equinox, will have a right ascension of around 23 hours. Stars closer to the vernal equinox will have a right ascension value closer to 0 sidereal hours. By contrast, declination measures the degree north or south a celestial object is from the celestial equator. On the celestial sphere, the celestial equator is an imaginary plane projected outward from the equatorial plane of Earth. It intersects the ecliptic, which can be considered the path drawn across the sky if it were a hollow dome and there was a giant pencil through the Earth while the Earth orbits the Sun, at the vernal and autumnal equinoxes. The reason why the equatorial plane and the ecliptic are not the same is a consequence of the Earth's axial tilt of 23.44 degrees. Concerning the observer, the zenith is the imaginary point directly above your head when looking at the night sky thus, if I say, “it's near the zenith” you should know that it is directly above my head.

Formed from the coalescence of debris from the collision of a Mars-sized object (Thea) into the Earth 4.5 billion years ago, the Moon is only natural satellite of Earth. The Moon is tidally locked to Earth, in other words, only one face of the Moon is visible from the Earth. Additionally, the phases of the Moon are caused by the exposure of the Sun's reflected off the Moon's surface in a given orientation of its orbit. In relation to its immediate appearance, since the Moon lacks an atmosphere, billions of years have scared the surface with numerous impact craters. As such, a surface layer called regolith was formed from the pulverized material which can be found across almost the entire surface of the Moon. Moreover, the Moon's surface is composed of light portions, called highlands, and dark portions called maria. The maria are vast pools of solidified basaltic lava that where formed 4.2 to 1.2 billion years ago. The highlands are anorthositic in composition and are older than visible maria thus, are more heavily cratered.

Richard. “Balancing an Equatorial Mount.” The Blog Formerly Known as McWiki, WordPress, https://themcdonalds.net/balancing-an-equatorial-mount/. Accessed 6 July 2022.