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Innovation in 2013

  • 27-12-2013 9:15am
    #1
    Orion36
    Banned (with Prison Access) Posts: 26 ✭


    The partitioning of retrogrades as seen from Earth is one of the nicer innovations this year where the resolution for the faster moving inner planets is different than apparent retrogrades resolution of the outer planets.

    Planets are called 'wanderers' by virtue that they appear to move forward-backwards-forwards against the background stars and the apparent backward/retrograde motion of the outer planets is a consequence of a faster moving Earth leaving them temporarily behind in view in our common orbital circuit -

    http://apod.nasa.gov/apod/ap011220.html

    Of course,this doesn't work for the inner planets as their apparent wandering motion against the background stars has an altogether different resolution.

    http://www.youtube.com/watch?feature=player_embedded&v=MdFrE7hWj0A

    Like observers in a stand watching cars go around a track,from our view on Earth we see Venus and Mercury swing out from behind the central Sun to their widest point in the opposite direction to the apparent motion of the background stars and then swing in front of the Sun and in the same direction as those stars -

    http://www.masil-astro-imaging.com/SWI/UV%20montage%20flat.jpg


    The background stars have two apparent motions - stellar circumpolar motion due to daily rotation and then the entirely separate apparent motion due to the Earth's orbital motion,something seen in the following animated graphic -

    http://www.youtube.com/watch?v=eeQwYrfmvoQ

    The inner retrograde resolution takes a little more effort to understand but it is every bit as satisfying as the more easily recognizable outer retrograde resolution.


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