eng Science and Education Publishing American Journal of Applied Mathematics and Statistics 2328-7292 2021-01-15 9 1 1 3 10.12691/ajams-9-1-1 AJAMS2021911 article Ilhan M. Izmirli iizmirl2@gmu.edu 1 George Mason University, United States In this paper, we will deal with the problem of calculating the average velocity of a celestial object revolving around another celestial object in an elliptical orbit. After proving our main theorem to this effect, we will give some alternate forms of the formula for the average velocity, and show that this average value is in fact, attained at certain points of the orbit. We will conclude the paper by providing an intuitively natural and straightforward amendment of this formula. http://pubs.sciepub.com/ajams/9/1/1/ajams-9-1-1.pdf average velocity of a planet first-order approximation second-order approximation