Re: Weather prediction

From: Stephan Szyman (
Date: Mon Sep 19 2005 - 04:46:50 EDT

  • Next message: Stephan Szyman: "iss boost?"

    hello george
    I watched ISS pass chicago just 12 degrees off the sw horizon over antares 
    (it passed over antares [which wasn't visible] at approximately 01:44:10 UTC 
    19 sept) on the orbit previous to your predicted pass, through scattered 
    it appeared to be exactly on time with the HA prediction chart.
    so unless a boost occured between my sighting of it and your predicted pass, 
      you should have seen it near vega just at 03:16:00 UTC 19 sept.
    the only reasons I can come up with as to why you may have missed it:
    1. your watch:  was it accurate?  I synch mine to the tones (which you can 
    hear by dialing WWVH broadcast (808) 335-4363)  fairly regulary... I've 
    found that just a little bit of error can cause you to miss an object,"  
    especially the dimmer ones.
    2. could one of the airliners you observed have been ISS?  if you don't see 
    a strobe, it's not an aircraft.  many times i have waited for ISS I have 
    seen it and then said to myself, " no, wait, that's an aircraft,  only to 
    determine after a few more seconds that it really was ISS.  if this was your 
    first attempt to observe ISS  it would have been easy and excusable to 
    mistake it for a jet.
    3. light pollution/cloudcover/atmospheric contamination:  I doubt it could 
    have been light pollution because i have seen ISS go past from the middle of 
    manhattan and also downtown chicago, and those are among the worst 
    light-polluted places on the planet.  cloudcover?  it seems unlikely,  if 
    you could see vega and the moon you probably should have seen ISS. perhaps 
    it was some freak combination of the two.  since the ISS entered the shadow 
    almost at the zenith,  it's possible that it slipped between some off-shore 
    cloudiness and the point where it entered the shadow at just the moment when 
    you were distracted by the chopper et cetera.  it only takes a moment's 
    distraction sometimes. also,  with LA being between you and the lower part 
    of the pass,  it could have been blocked until it got above 35 or 40 degrees 
    elevation by that pesky smog. were you able to observe cor caroli in canes 
    venatici or alkaid in ursa major?
    I suggest you make your watch (if it isn't already) accurate to within 1 
    second and tomorrow night  (tonight 19 sept PDT) at 19:06:28 PDT make sure 
    you are looking directly at caph and schedar in cassiopeia.  if at that time 
    you are able to see the principal stars of cassiopeia,  you will certainly 
    see the station pass between those two suckers.
    if we find out it was boosted between my sighting and your failure to sight 
    it,  disregard all this...  it appears that it was ready for a boost,  look 
    from what I am led to understand,  data on HA is usually up to 3 days old.
    clear skies!
    stephan szyman
    chicago IL USA
    41.6840N, 87.7000W; 188 msl
    16/2005 12:42:57 P.M. Pacific Standard Time,  Dinogeorge
    >I realize that the mind slows a bit with age, but I believe I am still
    >capable of reading a satellite ephemeris and accompanying star chart on 
    >which is
    >clearly printed that the ISS will appear in the NW on September 18, 2005 at
    >20:13 Pacific Daylight Time and will pass almost directly overhead in San 
    >  California something like 3 minutes later, pretty bright at magnitude 
    >After all, Vega is clearly marked on the chart and, by golly, IT was right
    >where  it was supposed to be, almost directly overhead. The sky was clear, 
    >moon was  just rising a day past full (so I know where, say, EAST is), and 
    >ISS? Well,  the ISS was NOT THERE.
    >I began watching shortly before 8 pm Sunday night,  eyes glued to the NW,
    >11x80 binoculars strapped around my neck. When my watch  said 8:15 and no 
    >sign of
    >the ISS I began to wonder what was going on. I did spot  a few airliners 
    >a helicopter during my little vigil, and to amuse myself  scanned the 
    >face as it slowly climbed upward from the horizon. By 8:30 I  decided that 
    >had somehow misread the chart and that maybe I should re-emerge  around 
    >9:00 in
    >case the chart had given standard time by mistake rather than  daylight 
    >Nope, no ISS at 9:15 either. By then evening clouds were  gathering, but a 
    >stars were still visible through the haze and I don't think  I could have
    >missed something as bright as the ISS.
    >I simply dunno what  happened; something is definitely amiss with the 
    >Above website. The  evening was rather a bust after that.
    >The same chart says the ISS will  pass over San Diego again from the NW on
    >Tuesday evening at about 7:30 pm, not  quite as high or as bright. Will I 
    >more time looking then?
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