The distance between celestial bodies, such as the Earth and the Sun, is typically measured using astronomical units (AU) or other distance units based on scientific conventions.
The average distance from the Earth to the Sun, known as an astronomical unit (AU), is defined as the mean distance between the centers of the Earth and the Sun. It is approximately 149.6 million kilometers (93 million miles). This distance is used as a fundamental reference point for measuring distances within the Solar System.
When calculating distances between celestial bodies, it is generally the distance between their centers that is considered. This is because celestial bodies can have different sizes, and measuring from the centers provides a consistent and standardized method.
It's important to note that the distance between celestial bodies can vary due to their elliptical orbits and other factors. Therefore, astronomers use average distances or calculate the distance at specific points in time based on orbital parameters.
Various methods are used to measure the distances to other celestial bodies, such as parallax measurements for nearby stars or radar measurements for objects within the Solar System. These techniques rely on triangulation or the measurement of time delays to determine distances accurately.
Overall, the distances between celestial bodies are calculated based on well-established scientific principles and measurement techniques, and they usually refer to the distances between the centers of the objects involved.