Positional astronomyPositional astronomy is the study of the positions of celestial objects. This is the oldest branch of astronomy and dates back to antiquity. Observations of celestial objects are important for religious and astrological purposes, as well as for timekeeping.
Ancient structures associated with positional astronomy include:
stars, of which about half are below the horizon at any one time.
- Planets which are in conjunction form a line which passes through the center of the solar system
- The ecliptic is the plane which contains the orbit of a planet, usually in reference to Earth
- Elongation refers to the angle formed by a planet, with respect to the system's center and a viewing point
- Superior planets have a larger orbit than the earth while the inferior planets (Mercury and Venus) orbit the sun inside the earth's orbit
- A transit occurs when an inferior planet passes through a point of conjunction