I'm a student who's trying to analyze some data for the distance between the earth and the moon (specifically, to model with sinusoidal functions in our math class.) In my research, I gathered some data, and I saw the expected changes in Earth-Moon distance (due to the elliptical orbit). However, I also saw that the distance at apogee and perigee changes as well:

Distance at apogee and perigee looks like a sinusoidal function, not constant

Why is this? I saw another question which asked why the time between apogee and perigee varied, and it was due to the effects of the sun. Edit: Looks like I misunderstood this, sorry. Could this phenomenon be because of the same reason as in the linked question?


  • $\begingroup$ Are we assuming the y-axis in your plot is measuring from Earth center to Moon center? $\endgroup$
    – cms
    Mar 2 '18 at 23:49
  • $\begingroup$ Yes, I'm pretty sure the data is from the Earth center to the Moon center. $\endgroup$ Mar 2 '18 at 23:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.