Are these real paths of planets as traced from Earth?

  • Few days a go, I came across these two pictures of paths of planets as observed from Earth. They have a perfect geometric shapes. Actually, to me they look so beautiful and perfect, that they appear fake or made by a pseudo-scientist or some propaganda society (e.g. flat Earth like community people) who talks about divine geometry etc.



    Auxiliary questions: Is this the reason, why Earth was consider to be in the center of the solar system?



    enter image description here



    enter image description here


    @MikeG sure I'll go through this link.

  • uhoh

    uhoh Correct answer

    3 years ago

    From this answer here are views of the inner and outer planets. I used the python package Skyfield which uses the NASA JPL ephemerides to generate positions of all the planets, then I subtracted the Earth's position to generate the geocentric positions.


    I agree with your guess that the first image is too perfect.


    The paths will not be closed, because there is not a rational number relationship (e.g. 5:9, 2:3, 1:1) between the periods of the planets.


    The ones in the image are reminiscent of the Spirograph drawings I used to make a very long time ago.





    ...plotting using the Python package Skyfield.


    The "inner" plotted bodies (from outer to inner) are Mars, (Earth), Moon, Venus, Mercury, The Sun. The data is for 2000 days.


    The "outer" plotted bodies are Uranus, Saturn, Jupiter, Earth, and The Sun. The data is for 2000 months.


    Distances are in AU.


    inner and outer planets, heliocentric and geocentric



    Are those "heliocentric" plots actually heliocentric, or barycentric? Although I do suspect one wouldn't be able to tell the difference at this scale...

    @JohnDvorak yep good point they are barycentric, I'd meant to subtract the Sun's position but it seems I forgot. I think the difference is probably less than 1 pixel, but accuracy is important, so I will regenerate the plots in the morning, and see if the difference is a pixel or not. Thanks!

    @JohnDvorak updated here and there The difference is roughly 1 vs 150 million km. It looks like more than 1 pixel when I plot them as much larger images and do the RGB subtraction, but then again so do the titles, so I don't think I'll pursue that further. Thanks again! https://i.stack.imgur.com/rcMcp.png

License under CC-BY-SA with attribution


Content dated before 7/24/2021 11:53 AM