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Old 03-02-2009, 03:48 AM
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iceman (Mike)
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Quote:
Originally Posted by Blue Skies View Post
Thanks of for the info.

I can't help wondering, however, why we aren't going to see any more transits this year. The ring plane crossing will last a while, surely Titan will transit a few more times than this?
hmm good point. The orbit of Titan is every ~16 days, so I guess you'd expect to see the transit every 16 days but after March 12th we don't see them until 2010.

Having a look in Starry Night Pro just then, it appears to be a combination of the rings opening back up again, so Titan passes below the disc, and the fact that the transit occurs 2 hours earlier each 16 days (the orbit is actually 15 days and 22 hours).

After March 12th, there's actually a Titan shadow transit on March 28th, while the Moon itself passes below the planet and that occurs at 8:46pm AEDST. Same again on April 13 and April 29 (the next 2 orbits). It appears to continue like this until Saturn is too low and too close to the Sun for us to observe. Also the shadow would start its transit 2 hours earlier each orbit, so it will be further across the planet each time until around July when the shadow transit is almost complete at the time the sun sets.

Thanks for asking the question - it prompted me to do some research and I actually learnt something!

Cheers
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