Re: Observed Lunar transit -- what did I see?

From: George Roberts (
Date: Thu Oct 16 2003 - 19:10:55 EDT

  • Next message: John Locker: "Re: Observed Lunar transit -- what did I see?"

    15-20 seconds implies distances on the order of 10,000 miles but objects
    that far would move mostly eastward so it would have to be even farther
    away.  At 10 arc seconds and 10,000 miles the object would have to be
    a half mile long.
    Much more likely the object was in the atmosphere.  A one foot balloon with 
    a note attached a few miles away.  Or an airplane (unlikely - would be much bigger
    than even 60 arc seconds).  Maybe a balloon with a second deflated balloon 
    hanging down.  Maybe some strangely shaped mylar balloon with something below
    it on a string.
    The wind could have carried the balloon towards, away, left or right making it look
    like it was going up down left or right or any angle between.
    - George Roberts
    ----- Original Message ----- 
    From: "David Ellsworth" <>
    To: <>
    Sent: Thursday, October 16, 2003 5:30 PM
    Subject: Observed Lunar transit -- what did I see?
    > Hello All,
    > I am new to this list, having seen my first lunar transit by a pure fluke 
    > last night!
    > I got a new 4" refractor a few days ago, and I was admiring the Moon at 
    > 65X. Then I saw this beautiful silhouette start to cross the disc... it was 
    > SO detailed. Taking a lazy 15-20 seconds to cross, I got a wonderful look 
    > at it! It was vertically oriented and had a clear separation between top 
    > and bottom halves; the top was narrow and the bottom was wider. The sides 
    > had visible detail in them -- they were not smoothly straight -- but in awe 
    > as I was  I did not think to make a mental snapshot and a quick sketch.
    > The crossing ended at 15 Oct 23:35:30 after crossing the Moon (altitude 
    > 19-d 37') from left to right and slightly upward oriented to the horizon, 
    > which translates to North-South and slightly West. Its velocity did not 
    > perceptible waver, and it became invisible after crossing the sunlit 
    > portion of the moon. I would estimate it to be 10-15 arc seconds in 
    > apparent height.
    > Here is an approximate simulation of what I saw: 
    > The simulated satellite is intentionally not antialiased, because there was 
    > a sharp delineation between top and bottom halves.
    > It is an amazing feeling to have seen something that nobody else on Earth 
    > saw! This has to be a virtual guarantee given how sensitive transits are to 
    > location.
    > I have not been able to find it using either J-Pass or CalSky. Is it 
    > possible I saw a satellite not in their databases? Given how long it took 
    > to transit, it would have had to be very far and therefore VERY large... IF 
    > it was moving perpendicular to me. Is it possible its path was extremely 
    > foreshortened because it was moving toward me?
    > Or is it more likely that it wasn't a satellite? I'm open to speculation. 
    > What could it have been? The mystery of the thing is driving me nuts!
    > Regards,
    > David
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