The Surprisingly Unknown

[impactcrater]

According to NASA the length of a Saturnian Day is unknown...who would have thought ?

[Dave In Vermont]

The length of a day on Saturn has recently been deduced. Oddly, it was a mystery for an inordinate period compared to other planets <drum-roll, please>:

"Astronomers now agree on an average day of 10 hours, 32 minutes and 35 seconds." - Universe Today - by Fraser Cain

Here's the article:

https://www.universetoday.com/15418/interesting-facts-about-saturn/

And how about the article as a Pdf?

Ten Interesting Facts About Saturn.pdf

Have fun!

Dave

[SteveNickolls]

7 hours ago, Dave In Vermont said:

The length of a day on Saturn has recently been deduced.

August 6th 1933-http://adsabs.harvard.edu/full/2009JBAA..119...67M 10 hours 16 minutes and 17 seconds. Not bad for an old theatrical performer.

Cheers,
Steve

[SilverAstro]

"Unknown" - ?  I suppose it depends on one's precise definition of how much unknown ! I thought surely not, it has been about 10h and a bit all the time I have known Saturn ( over 60y!) so I reached for my trusty "Handbook of the Heavens" Bernhard/Bennet/Rice 1957 an lo! 10h14m. That is good enough I'd have thought Anyhows, how do you time a bunch of clouds to a few seconds ?!

 

[Dave In Vermont]

That's likely why it wasn't until recently that it was accurized at the 10h32m35s mark. Perhaps by bouncing a RADAR through the clouds and off whatever serves as it's solid core?

I smell a Cassini.....

Dave

[The Admiral]

3 hours ago, SteveNickolls said:

August 6th 1933-http://adsabs.harvard.edu/full/2009JBAA..119...67M 10 hours 16 minutes and 17 seconds. Not bad for an old theatrical performer.

Cheers,
Steve

Thanks for posting a link to this fascinating individual, Steve. A man of many talents.

Ian

[impactcrater]

https://www.nasa.gov/mission_pages/cassini/media/cassini-062804.html

not all it seems....

[impactcrater]

https://www.nasa.gov/feature/jpl/saturn-surprises-as-cassini-continues-its-grand-finale

and this too

[The Admiral]

Fascinating links, thanks for posting.

So what is meant by rotational period? To me it seems inconceivable that it would rotate as a rigid body, but I can imagine the period varying with both depth and latitude.

Ian

[impactcrater]

nice in Oxfordshire....I lived in Maidenhead for  6 months....I assume it is the rotation of the metal hydrogen core . Is that true of the Jupiter ? NASA says it matters to create a weather model . so handy here on Earth!

[The Admiral]

5 hours ago, impactcrater said:

nice in Oxfordshire....I lived in Maidenhead for  6 months....I assume it is the rotation of the metal hydrogen core . Is that true of the Jupiter ? NASA says it matters to create a weather model . so handy here on Earth!

Could be a lot worse!

I wondered if it referred to the solid core, but I don't see why the magnetic field should necessarily be locked to it. I guess there's some maths to say it is, but clearly there is some slippage going on otherwise they wouldn't have seen the apparent slowing down. I hope they get a better model than we've got here! Never seems to be right, for astronomy at least .

Ian

[LukeSkywatcher]

Saturn and Jupiter have roughly the same period of rotation on their axis............making a day on each planet last about 10 hrs............give or take. I guess its easier to measure on Jupiter visually because it has more visible features which when observed can be timed.

[Stub Mandrel]

Imagine trying to decide how long an 'Earth Day' is by just tracking clouds - and without any mountains to keep some in the same place...

[SilverAstro]

2 hours ago, LukeSkywatcher said:

making a day on each planet last about 10 hrs

I wonder if they are entangled ?

 

5 minutes ago, Stub Mandrel said:

Imagine trying to decide how long an 'Earth Day' is by just tracking clouds

I believe I did that earlier also   'bunch of ' clouds I think it was

I still have not worked out quite why they are excersised about it, not as though you wanted to land in London, not London,Ontario or London,Saturn ??  I mean look at the bother Jupiter's RedSpot gives us when we try to prescribe it in Stellarium