Re: Iridium's seam

Björn Gimle (
Wed, 14 Apr 1999 08:47:56 +0200

>the constellation's  seam  is a kind of constellation's reference, it's
>the point  where the first orbital plane and the latest orbital plane are
>adjacents;and they go in contrary directions.
>How can I do to calculate its position?

You can inspect an Iridiums TLE file, like
where the Epochs are all fairly recent/similar, and see that the ascending
nodes are from about 118 degrees over 150, 180... to 276  on Apr.14

Or you can run predictions from a point near Earth's center (with a program
like SkyMap that can handle 'any' site height) and see that the nortbound
tracks pass east of Canis Minor - Gemini, and the southbound ones in the
eastern part of Orion, and west thereof (as of Apr.14)

(Image attached to Marcela Botero's copy)

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