
Hurricane on Saturn - karolisd
http://www.nasa.gov/mission_pages/cassini/multimedia/pia14944.html
======
btilly
A random note for those who might wonder what "N" and "S" mean on another
planet.

Take your right hand out. Stick your thumb up. Curl your fingers around. Your
thumb represents a planet's N pole, and your fingers point in the direction
that the planet is spinning. (The Earth moves from W to E, and the result is
that it looks like the Sun rises in the E. Sit down a globe and a flashlight
if this comment makes no sense.)

For any spinning thing we can do the same exercise. Just wrap your fingers of
your right hand around in the direction of the spin, stick your thumb up, and
that is the North pole of that spin.

Now for the fun fact. Most of the stuff in the Solar System rotates roughly
the same way. It doesn't matter whether you take the rotation of the Earth,
the rotation of the Moon, the orbit of the Moon around the Earth, the orbit of
the Earth around the Sun, the orbit of Saturn around the Sun, the rotation of
Saturn, the orbits of Saturn's moons around Saturn - the north poles of all of
these are reasonably well aligned.

They are not exactly aligned. For instance the Earth's rotational axis is
tilted 23.5 degrees from the axis of its orbit around the Sun. (Hence our
seasons.) And not everything follows the rule. Uranus is the best-known
exception. But most of it lines up fairly well.

The only actual use that I've ever found for this fact is being able to
explain to my son why the Moon rises later every night, but I've always
thought that it was pretty cool.

 _EDIT:_ glurgh below corrected my understanding. It happens that for most of
the planets, North corresponds to the right hand rule as I described. But
that's not actually the way it is defined and Venus in particular does not
work that way.

~~~
glurgh
This is only for minor bodies, not planets. The poles of planets are pretty
much defined to be 'pointed the same way as the Earth's'. The north pole of
Venus is roughly aligned with the north pole of the Earth despite the fact
that Venus's rotation is retrograde.

See

<http://en.wikipedia.org/wiki/Poles_of_astronomical_bodies>

~~~
btilly
Thank you for the correction.

I tend to pick up fun trivia, but I'm not an expert, and always appreciate
when someone corrects mistakes in my understanding.

~~~
glurgh
I didn't know either! Makes sense geometrically but I wondered is it really
the case that when you read something like 'image of the North pole of Venus',
it's really the opposite pole. It looks like astronomers rely on the
'convenient' convention until they can't and then fall back to the
mathematical one.

~~~
btilly
You made me curious. According to
[http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980225a....](http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980225a.html)
there is no real connection between the direction of rotation within the Solar
System and the Sun's orbit around the Milky Way. And again the Milky Way's
rotation has little to do with its motion in the local group.

However across the Milky Way there are again a whole lot of things roughly
moving in the same direction.

~~~
glurgh
It looks like the Galactic Coordinate System (which, sensibly but to the
confusion of the casual reader is centered on the Sun) is also 'backwards'
with respect to the right hand rule. The galactic north pole is actually the
galactic rotational south pole. This seems to be because the coordinate system
was based on the rotational direction of the Sun.

I think I may have just exceeded my recommended daily nerdallowance of reading
about spinning things in the sky.

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nostromo
Non-false color image:
[http://www.nasa.gov/mission_pages/cassini/multimedia/pia1494...](http://www.nasa.gov/mission_pages/cassini/multimedia/pia14945.html)

~~~
krschultz
Good post. The false color images make me fear that actual space will be
disappointing for people to look at.

~~~
habosa
For some reason this small comment made me very sad. I'd hate to imagine that
our human desire for sensationalism could make the sight of outer space bland
to a desensitized public. I have the APOD set as my phone's background every
morning and I am always astounded at the incredible array of colors and the
degree of contrast. I never really thought that I was being fooled.

It sucks that I really do think the non-false color image is boring, because
that should be really exciting to someone who enjoys thinking about the
universe like I do. Although I still think my mind would fucking explode if I
ever got to go deep into space.

~~~
fletchowns
Oh calm down. You're not being fooled. These images are falsely colored for a
reason. They really complement each other, not the other way around.

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btipling
Not discounting how amazing that picture is, but it is false color.

~~~
wmeredith
It is a bit silly. "This thing we found resembles a rose, because after we
found it, we colored it like a rose." WTF?

It's an amazing image to be sure, but why all that nonsense?

~~~
btilly
It is false color because it has to be.

If you're sending a camera from here to another planet, it makes no sense to
send a camera that takes pictures in the same wavelengths that we see so you
can claim true color. Instead you pick wavelengths that for whatever
scientific reasons you think will be most informative.

And then once you have that information, for humans to understand it, it makes
no sense to leave it as raw binary data. Instead you map some of the
wavelengths that you've got onto wavelengths that our eyes can see, and
trained human eyes can identify and understand features very quickly. But at
that point you've got a false color picture.

~~~
spacemanaki
But here's a "natural-color" image of the same hurricane:

[http://www.nasa.gov/mission_pages/cassini/multimedia/pia1494...](http://www.nasa.gov/mission_pages/cassini/multimedia/pia14945.html)

"Images with red, green and blue spectral filters were combined to create this
natural-color view, which is what the human eye would see if we were there at
Saturn."

~~~
btilly
So that satellite has that capability. But not all do.

Comparing natural color and false color, it is clear to me that false color is
more convenient for trying to pick out features in the picture.

~~~
spacemanaki
I don't think anyone's disputing that false color could be useful to
scientists or that we should put cameras on satellites that capture true color
images for the benefit of blog posts targeting the general public, and I
certainly was not claiming anything like that, being horribly under-qualified.
But waxing poetic about "the red rose of Saturn" is a little bit _silly_ IMHO,
but it's nothing worse than that...

<http://www.ciclops.org/view_event/191/The_Red_Rose_Of_Saturn>

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aashaykumar92
I've linked the official NASA news release below as the explanation in this
link didn't suffice for my interest in this!

[http://www.nasa.gov/home/hqnews/2013/apr/HQ_13-121_Saturn_Hu...](http://www.nasa.gov/home/hqnews/2013/apr/HQ_13-121_Saturn_Hurricane.html)

~~~
netcraft
Another link with a video:
[http://www.nasa.gov/mission_pages/cassini/whycassini/cassini...](http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20130429.html)

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prg318
The Black Metal band "Fell Voices" [1] is using the uncolored image in OP as
the album art for their next record "regnum saturni" [2]. Beautiful picture
with or without color!

[1] <http://fellvoices.blogspot.com/>

[2] [http://fellvoices.blogspot.com/2013/03/regnum-saturni-
europe...](http://fellvoices.blogspot.com/2013/03/regnum-saturni-european-
press-out-now.html)

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barbs
Anyone found a good high-quality version of 'the rose' suitable for use as a
desktop background? The one they have on the site appears to be too small.

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raverbashing
Makes me wonder how distant planets can have such extreme meteorological
phenomena while being so far from the sun.

In Earth this is powered mainly by the temperature differences caused by the
Sun.

~~~
glurgh
Saturn is about ten times larger than the Earth in diameter while spinning
more than two times faster. Additionally, Saturn is 'self-luminous', it
generates more energy than it receives from the Sun.

"Saturn has a very hot interior, reaching 11,700 °C at the core, and the
planet radiates 2.5 times more energy into space than it receives from the
Sun. Most of this extra energy is generated by the Kelvin–Helmholtz mechanism
of slow gravitational compression, but this alone may not be sufficient to
explain Saturn's heat production. An additional mechanism may be at play
whereby Saturn generates some of its heat through the "raining out" of
droplets of helium deep in its interior" [Wikipedia]

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dmix
Shame it's not a wide angle shot. Would have made a beautiful desktop
background.

~~~
Freaky
Wider shot, sadly sans colour, but plus another awesome weather phenomenon:
<http://apod.nasa.gov/apod/ap130220.html>

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atgm
I was disappointed when I realized that the image of Africa in the background
wasn't for scale.

~~~
DanBC
A good point. Here's a website that lets you draw circles on maps.

(<http://obeattie.github.io/gmaps-radius/>)

~~~
atgm
Thanks!

Strange -- the storm is both larger and smaller than I would have expected.

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kingkawn
Reminds me of: [http://www.surenmanvelyan.com/eyes/your-beautiful-
eyes/?wppa...](http://www.surenmanvelyan.com/eyes/your-beautiful-eyes/?wppa-
album=5&wppa-cover=0&wppa-occur=1)

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sidcool
This is scary. That size of a storm can wipe out a big part of the country.

