Re: UNID crossing the Moon

From: Björn Gimle (bjorn.gimle@gmail.com)
Date: Wed Oct 12 2011 - 16:53:11 UTC

  • Next message: Bram Dorreman: "Re: Slow tumbling sat"

    It would be interesting to see a still image, and how you arrived at the 4"
    size.
    
    But even more useful for identification of a possible/likely satellite is
    the exact time of passage!
    
    2011/10/12 Giuseppe N. Gerbore <giuseppegerbore@virgilio.it>
    
    > Yesterday night I captured by chance something crossing the Moon:
    > http://www.youtube.com/watch?v=XWUi4wIWnO8
    >
    > Seems to me a satellite, but .. let us do some calculation:
    >
    > Data:
    >
    > Image angle                4''
    >
    > Captured path             15'
    >
    > Transit time                1.93s
    >
    >
    >
    > By using the approximate relation: sin(A)=Diametre/Range:
    >
    >
    >
    > 1) Plane (D=50m)                  Range             =50/sin(4'')
    >       =2 578 310 m
    >
    >                                               Path
    >  =50*60*15/4              =      11 250 m
    >
    >                                               Velocity          =11
    > 250/1.93              =       5 829 m/s
    >
    > 2) Satellite (D=10m)             Range             =10/sin(4'')
    >     =   515 662 m
    >
    >                                               Path
    >  =10*60*15/4              =       2 250 m
    >
    >                                               Velocity          =2 250/1.93
    >                =       1 165 m/s
    >
    > 3)Bird (D=0.3m)                    Range             =0.3/sin(4'')
    >        =     15 469 m
    >
    >                                               Path
    >  =0.3*60*15/4             =          67.5 m
    >
    >                                               Velocity          =67.5/1.93
    >                  =         34.9 m/s
    >
    > 4) Mosquito (D=0.005m)       Range             =0.005/sin(4'')           =
    >           257 m
    >
    >                                               Path
    >  =0.005*60*15/4         =        1.125 m
    >
    >                                               Velocity          =1 125/1.93
    >                =          0.58 m/s
    >
    >
    >
    > Velocity assumed at right angle with line of sight. Might be much more if
    > object approaching or moving away from the observer.
    >
    >
    >
    > Am I talking complete nonsense?
    >
    >
    >
    >
    >
    > Giuseppe
    >
    >
    >
    > Casa, 44.64°N, 10.90°E, 57m asl.
    >
    > -------------- next part --------------
    > An HTML attachment was scrubbed...
    > URL:
    > http://mailman.satobs.org/mailman/private/seesat-l/attachments/20111012/7bf3ba13/attachment.html
    > _______________________________________________
    > Seesat-l mailing list
    > http://mailman.satobs.org/mailman/listinfo/seesat-l
    >
    
    
    
    -- 
    ----------------------------------------
    Björn Gimle, COSPAR 5919
    59.2576 N, 18.6172 E, 23 m
    Phone: +46 (0)8 571 43 312
    Mobile: +46 (0) 704 385 486
    -------------- next part --------------
    An HTML attachment was scrubbed...
    URL: http://mailman.satobs.org/mailman/private/seesat-l/attachments/20111012/c04019a8/attachment.html 
    _______________________________________________
    Seesat-l mailing list
    http://mailman.satobs.org/mailman/listinfo/seesat-l
    



    This archive was generated by hypermail 2b29 : Wed Oct 12 2011 - 16:54:40 UTC