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When two predictions conflict

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#1 bunyon

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Posted 30 October 2013 - 09:14 PM

Cal Sky predicts a ISS transit across the moon for Nov. 7 for me. The centerline passes within a mile of my house.

However, Sky Safari has ISS missing the moon by half a degree.

Which, if either, should I trust?

#2 GlennLeDrew

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Posted 31 October 2013 - 01:09 AM

Which is using the more recent orbital elements?

#3 bunyon

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Posted 31 October 2013 - 07:24 AM

How would I determine that?

#4 GlennLeDrew

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Posted 02 November 2013 - 05:57 AM

If you can peruse the data file containing the satellite orbital elements, there may be a header stating the epoch date. I'm just guessing here, as I've never downloaded such data for any of my planetarium software. If you've never updated these elements for your software, predictions will become significantly in error in a matter of weeks. The safe thing is to update those elements reasonably frequently. After doing this, let us know if the different software predictions have become more congruent...

#5 bunyon

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Posted 02 November 2013 - 12:49 PM

It looks like CalSky is more recent. We'll see.

Or not...supposed to rain the day of the transit.

Thanks.






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