Before 2012, what did the AU conceptually represent, leading to slight variations in its measurement?

Answer

The average distance between the center of the Earth and the center of the Sun

Historically, the AU represented the average distance between the center of the Earth and the center of the Sun, and because the Earth’s orbit is slightly elliptical, this distance constantly changed.

Before 2012, what did the AU conceptually represent, leading to slight variations in its measurement?

#Videos

Units in Astronomy: Explained! - YouTube

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