Transit finder help Other · Steven · ... · 2 · 60 · 0

Hello everyone, 

I'm trying to get an ISS transit pic, so.. naturally.. transit-finder is the place to figure out when it happens.

Several times now, I've had transits listed on the website. You get excited, you buy more equipment, you test the equipement, you plan the drive/location.. you go back on transit-finder to double check the time…… and…  the transit is gone.. 
Did the moon move? did the earth speed up? did Boeing mess-up of leaving 2 astronauts stranded affect the ISS orbit?

I was under the impression that orbits were accurate enough to predict things - Yes, I know it says on the website that anything beyond 2 weeks is a prediction.  That's why I'm only looking within a 2 week period, and double check transits closer to the date. And I was going to have a transit at my location in 4 days. And now that has completely disappeared from the list… again.. and that's getting a little frustrating.

I can recall using transit-finder 2-3 years ago, and I didn't feel it was like this, and was always accurate, transits always remained on the same dates, with only times changing slightly… Did something change? I did move from 48 degrees north to 24 degrees north which might affect things a little? I would assume there are larger distances and such to deal with closer to the equator.. but even increasing the range doesn't make the transit appear again..

So, any help / tips / tricks on getting transits accurately, and making sure they still happen, are appreciated.

Thanks

One of the problems with trying to look too far ahead is that the ISS occasionally boosts itself to a slightly higher orbit. It doesn’t take the orbit changing much at all to ruin a transit. 

In general, I’ve had success with transits that are 3-4 days in the future. I’d say you just had really bad luck with the one 4 days out.