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APOD: In the Center of Saturns North Polar... (2012 Dec 04)
Posted: Tue Dec 04, 2012 5:06 am
by APOD Robot
In the Center of Saturns North Polar Vortex
Explanation: What's happening at the north pole of Saturn? A
vortex of strange and complex swirling clouds. The center of this vortex was
imaged in unprecedented detail last week by the robotic
Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual
hexagonal cloud system that surrounds the north pole of Saturn. The sun rose on Saturn's north pole just a few years ago, with Cassini taking only
infrared images of the shadowed region previously. The
above image is raw and
unprocessed and is being prepared for release in 2013. Several
similar images of the region have recently been condensed into a
movie. Planetary scientists are sure to continue to study this most
unusual cloud formation for quite some time.
[/b]
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 5:21 am
by bystander
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 5:24 am
by Beyond
The video looks like a Giant type of worms mouth, getting ready to devour Cleveland, or Tokyo.
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 9:20 am
by Boomer12k
The amazing thing to me is they appear to be very "fluffy". Like a Cotton Candy Machine or something. The winds must be really whipping!
Go Cassini!
:---[===] *
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 11:54 am
by saturno2
Saturn, Saturn
The mysterious planet
The hexagonal cloud system in the North Polar of Saturn
Why hexagonal?
Perhaps, "different" magnetic field?
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 11:58 am
by starsurfer
WOW that is amazing for unprocessed raw data! I love Saturn and its neverending surprises!
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 1:00 pm
by orin stepanek
I think it looks a lot like a whirlpool galaxy!
![Cool 8-)](./images/smilies/icon_cool.gif)
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 1:53 pm
by neufer
Boomer12k wrote:
The amazing thing to me is they appear to be very "fluffy". Like a Cotton Candy Machine or something. The winds must be really whipping!
http://en.wikipedia.org/wiki/Cotton_candy wrote:
<<Cotton candy (US, India, Canada), candy floss or candyfloss (UK, Ireland, Canada, New Zealand and South Africa), or fairy floss (Australia) is a form of spun sugar. Food coloring can be used to change the natural white color. There are many flavors, including strawberry, lemonade, blueberry, lime, grape, orange, watermelon, pineapple mango, and more.
Cotton candy was first recorded in the 16th century. Machine-spun cotton candy was invented in 1897
by the dentist William Morrison and confectioner John C. Wharton and first introduced to a wide audience at the 1904 World's Fair as "Fairy Floss" with great success, selling 68,655 boxes at the then-high price of 25¢, half the cost of admission to the fair (equivalent to $6 today).
Joseph Lascaux, a dentist from New Orleans, Louisiana, invented a similar cotton candy machine in 1921. In fact, Lascaux patent named the sweet confection “cotton candy” and the fairy floss name faded away, although it retains this name in Australia.
Typical machines used to make cotton candy include a spinning head enclosing a small "sugar reserve" bowl into which a charge of granulated, colored sugar (or separate sugar and food coloring) is poured. Heaters near the rim of the head melt the sugar, which is squeezed out through tiny holes by centrifugal force. The molten sugar solidifies in the air and is caught in a larger bowl which totally surrounds the spinning head. Left to operate for a period, the cotton-like product builds up on the inside walls of the larger bowl, at which point the machine operator twirls a stick, cone, or their hands around the rim of the large catching bowl, gathering the sugar strands into portions which are served on stick or cone, or in plastic bags. The product is sensitive to humidity, and in humid summer locales, the process can be messy and sticky.>>
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 2:07 pm
by Ann
Today's APOD looks like hot chocolate with whipped cream going down the drain!
Ann
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 2:53 pm
by moonstruck
Double WOW!! Go Cassini.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 3:04 pm
by mwhidden
Is it really accurate to say that the north pole "precessed" into sunlight? I would assume it came into sunlight due to the tilt of the axis and its position in orbit. Precession is a different phenomenon, isn't it?
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 3:14 pm
by APODFORIST
This reminds me to Stanislaw Lem's Solaris.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:01 pm
by Chris Peterson
mwhidden wrote:Is it really accurate to say that the north pole "precessed" into sunlight? I would assume it came into sunlight due to the tilt of the axis and it's position in orbit. Precession is a different phenomenon, isn't it?
It's arguable that the terminology isn't
strictly incorrect, since in common usage "precession" is sometimes used to describe the sort of cone created when a tilted body revolves around something else. But that's not the scientific usage, and given that this is a scientific site, I agree with you that "precession" is a poor word choice.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:20 pm
by neufer
Chris Peterson wrote:mwhidden wrote:
Is it really accurate to say that the north pole "precessed" into sunlight? I would assume it came into sunlight due to the tilt of the axis and it's position in orbit. Precession is a different phenomenon, isn't it?
It's arguable that the terminology isn't
strictly incorrect, since in common usage "precession" is sometimes used to describe the sort of cone created when a tilted body revolves around something else. But that's not the scientific usage, and given that this is a scientific site, I agree with you that "precession" is a poor word choice.
"Precession" is the wrong word choice.
http://aas.org/archives/BAAS/v31n4/dps99/451.htm wrote:
Ring plane crossings and Saturn's pole precession.
P.D. Nicholson (Cornell), R.G. French (Wellesley), A.S. Bosh (Lowell)
<<The predicted precession rate of Saturn's pole, due principally to the indirect solar torque on Titan, is -0.738" yr-1, corresponding to
a period of 1.76~My (French et al. [1993] Icarus 103, 163). Analysis of subsets of Voyager, ground-based (28 Sgr, July 1989) and 1991 HST occultation data led to best-fit annual rates of -0.63''±.23'' (French et al. 1993) and -0.41''±.19'' (Bosh [1994] Ph.D. thesis, MIT). The latter is only 55% of the predicted rate. Precise observations of Saturn's ring plane crossings provide an independent method for determining the planet's axial precession rate. Combining the known pole position at the time of the Voyager encounters with the observed time of ring plane crossing on 22 May 1995, Bosh et al. [1997] (Icarus 129, 555) derived an annual rate of -0.52''±.07'', consistent with the occultation results and again significantly less than the predicted value.
An analysis of 22 reported times of ring plane crossing, extending over a period of 280~yr, leads to a very similar estimate of the pole precession rate of -0.51''±.14''~yr-1, which is completely independent of the occultation data (Nicholson & French [1997] BAAS 29, 1097). The most important observations are those made with HST in May and August 1995 (Bosh et al. 1997; Nicholson et al. 1996 [ Science 272, 509]), at Pic du Midi in 1966 (Dollfus 1979 A. & A. 75, 204), and at Johannesberg and Yerkes in 1907/08 (Innes 1908 MNRAS 68, 32); Barnard 1908 Ibid 68, 346). The time used for the 10 August 1995 crossing is that reported for the west ansa (20:20±8~min UT), as the east ansa was partially obscured by the F Ring at this time. It now appears that the low precession rate is primarily a consequence of Titan's proper inclination of 0.32\circ, which leads to a slow variation in the torque exerted on Saturn with a period of ~00~yr, Titan's nodal regression period. At the present time, the torque is close to its minimum value. The nutation model of Vienne & Duriez [1992] (A & A 257, 331) in fact predicts an average precession rate of -0.50''~yr-1 over the last 100~yr, 68% of the secular rate and in excellent agreement with the observations.>>
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:30 pm
by potoole
Can someone provide a sense of scale? I'm guessing this shot is about the diameter of the Earth, is that about right?
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:31 pm
by rjgjr
Pizza planet !!! : )
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:42 pm
by Chris Peterson
neufer wrote:"Precession" is the wrong word choice.
I'm sticking with my original assessment, that it's simply a
poor word choice.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 4:55 pm
by Canadian Grandma
To me it looks like the mats and coasters now so popular made from felted wool.
Re: APOD: In the Center of Saturn's North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 5:02 pm
by LocalColor
Fascinating!
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 5:49 pm
by jisles
The precession period of Saturn's spin axis is about 1.8 million years. The north pole didn't precess into sunlight a few years ago, as stated in today's IPOD. It moved into sunlight as a result of Saturn's orbital motion.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 5:52 pm
by jisles
... but I see the point has already been covered!
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 7:29 pm
by quigley
"Fascinating."
Why does this phenomenon not occur on our own planet? Would we have to live on a gas giant.
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 7:59 pm
by Anthony Barreiro
quigley wrote:"Fascinating."
Why does this phenomenon not occur on our own planet? Would we have to live on a gas giant.
We do have polar vortices on Earth:
http://en.wikipedia.org/wiki/Polar_vortex
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Tue Dec 04, 2012 9:16 pm
by neufer
Anthony Barreiro wrote:quigley wrote:
"Fascinating."
Why does this phenomenon not occur on our own planet? Would we have to live on a gas giant.
We do have polar vortices on Earth:
http://en.wikipedia.org/wiki/Polar_vortex
Polar vortices often with
nearly hexagonal structure
(If only those darn continents didn't get in the way
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
)
Re: APOD: In the Center of Saturns North Polar... (2012 Dec
Posted: Wed Dec 05, 2012 12:25 am
by flash
potoole wrote:Can someone provide a sense of scale? I'm guessing this shot is about the diameter of the Earth, is that about right?
And how fast are these clouds moving?