
Jupiter’s North Pole Unlike Anything Encountered in Solar System - betolink
https://www.nasa.gov/feature/jpl/jupiter-s-north-pole-unlike-anything-encountered-in-solar-system
======
krylon
Ignoring all the fascinating stuff about Jupiter, let me point out this gem:
_The download of six megabytes of data [...] took one-and-a-half days_

I sometimes like to scare kids by telling them about the time when I surfed
the Internet with 14.4 kbit modem, but even that looks incredibly fast
compared to the speed of interplanetary data transmission (back then, 6 MiB
would have taken me about 2-2.5 hours).

(NB that I am not complaining or anything, just pointing out that this is many
orders of magnitudes slower than anything one would normally consider a "slow"
connection.)

~~~
btgeekboy
It's also fascinating to think about how TCP is ineffective at that distance.

[https://en.wikipedia.org/wiki/Interplanetary_Internet](https://en.wikipedia.org/wiki/Interplanetary_Internet)
is a good starting point to learn more.

~~~
visarga
That means when humans finally colonize Mars, there will be two FaceBooks, FB
Mars and FB Earth, with any communication between them running at a lag.

I bet there will be AI research to create bots to act in "real time" on your
behalf on the opposite planet. If the artificial agent can imitate your own
actions and judgements, it would be a good way to surpass the speed of light.
It will be necessary to build these agents because other interested parties
could use the time lag to unfairly gain an advantage over you. The more we
explore, the larger the time lag. With Jupyter it is 33-53 minutes. With Pluto
it's 5h. The nearest star - 4 years. The Moon is at 1.3s.

~~~
zeroer
The last thing I need is a realtime Facebook now. I feel like I should build
in a delay of ~1 week to everything I do.

~~~
zachrose
Yes. I world also like to see the delay randomized between 3 and 10 days so
that nobody can tell what tempo you're replying at.

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jobu
_“Saturn has a hexagon at the north pole,” said Bolton. “There is nothing on
Jupiter that anywhere near resembles that. The largest planet in our solar
system is truly unique. We have 36 more flybys to study just how unique it
really is.”_

This is the first I've heard of Saturn's hexagon, very interesting:
[http://www.space.com/30608-mysterious-saturn-hexagon-
explain...](http://www.space.com/30608-mysterious-saturn-hexagon-
explained.html)

~~~
SilasX
>The largest planet in our solar system is truly unique.

Hold on -- how much do we know about the poles of gas giants in other solar
systems? I'm guessing we can't get a good look or anything...

Edit: added quote to clarify what I was responding to.

~~~
undersuit
Saturn has a tilt just a bit more than the Earth and it experiences seasons;
the pole is rotated something like 26 degrees into our field of vision in
"winter". Uranus is actually rotating on it's side.

[http://www.setterfield.org/Astronomy/pictures/axial-tilt-
pla...](http://www.setterfield.org/Astronomy/pictures/axial-tilt-planets.jpg)

~~~
tome
" _other_ solar systems"

~~~
undersuit
The answer is we don't. Unlike the other three gas giants in the Solar System
we can't see Jupiter's pole clearly. So Jupiter is unique to our solar system,
and we don't know much about the visual details of exoplanets.

~~~
perseusprime11
Is Jupiter all gas or does it have any mass? It is hard for m kind to imagine
a big ball of gas looking like a planet and going around the sun

~~~
grkvlt
The thing is, there's a _lot_ of gas, which like any other matter, has mass.
So, even though a hydrogen atom is the lightest element possible, and we think
of hydrogen gas a being light, that's just relative to other things. At a
human scale, it isn't possible to have that much of the stuff around. But you
can always go and collect a lot of it; in fact if you get ten to the power
twenty seven kilograms of the stuff, and put it in one place, gravity will
shape it into a sphere that looks very like Jupiter. Or, get 1000 times as
much as that, and watch as gravity squeezes it so much it begins to fuse into
helium at the centre - you'll have a star the size of our Sun...!

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dmreedy
Absolutely breathtaking.

Interesting that they phrase the headline almost as if to imply uniqueness. My
impression was that Saturn's hexagon was the unique situation (occurring,
hypothetically, only under very specific conditions). Is it expected then that
Uranus and Neptune's poles will look different still?

~~~
mcguire
Uranus has an axial tilt of around 90°, so it is undoubtedly completely wacky.
I have no idea what Neptune's looks like.

~~~
gregwtmtno
No one does. Neptune and Uranus have been visited by only Voyager 2. Neptune's
pole wasn't covered in the flyby.

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jl6
I understand Juno flew as close as 4,200km. Are there any pictures from that
distance? The closest here says it was taken from 38,000km.

~~~
Diederich
Given the exceptionally slow transfer rate, I suspect we will be seeing even
better images over the next few weeks.

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jpfed
I wonder if the clouds don't separate into bands as much at those latitudes
because the velocity (due to the planet's rotation) is lower closer to the
poles.

~~~
astazangasta
The Coriolis force is strongest at the poles and weakest at the equator, so I
presume there would be more rotation and thus less banding near the poles due
to this effect.

The origin of the banding is supposedly similar to the banding on Earth, which
has three broad 'bands' driven by Hadley cells (polar, mid-lattitude,
tropical), driven by convective heating moving energy away from the equator
towards the poles, except presumably Jupiter has much more energy and
therefore more convection and more bands.

I only have a very crude understanding of atmospheric forces, though, so
paging someone who knows better.

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powera
There are only 8 planets in the solar system (well, 9 with Pluto). "Unique"
isn't a terribly high bar here.

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justifier
the second video says:

> the infrared data captured a faint aurora

when talking about aurora strength which variable is predominant: the
magnetosphere, the atmosphere, or amount of solar radiation?

also, can anyone speak to the reason for the noisy instrument detecting those
3.45 micron wavelengths? why is the bottom edge so active?

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numlocked
"The download of six megabytes of data collected during the six-hour transit,
from above Jupiter’s north pole to below its south pole, took one-and-a-half
days."

...surely that's a typo and they mean gigabytes?

~~~
doikor
The solar panels that Juno has produce only 500 watts of power. You would need
a lot more then that to be sending gigabytes of data in any meaningful
timeframe. So yes it really is just six megabytes of data taking 30h+ to
download. Btw the panels would produce 14kW at earth orbit but suns power goes
down quite fast as you move away from it. Also the farthest from the Sun we've
ever used solar panels. Traditionally missions this far from the Sun have used
some kind of a nuclear power source (RTGs). Though I don't think they could
produce 500 watts without being very big.

[http://www.jpl.nasa.gov/news/news.php?feature=4818](http://www.jpl.nasa.gov/news/news.php?feature=4818)

~~~
jnicholasp
Transmission is one thing, but collection is another: did they really only
collect 6 megabytes of data over the course of a 6 hour flyby?

Off topic, ish: does anyone know how large a solar panel array would have to
be to supply all of our current energy use, if the array orbited the Sun at
the same distance Mercury does?

~~~
daeken
According to Wikipedia, the world's average energy consumption is 12.3Tw.
Given that the Earth is gets 1366 W/m² of solar power at 149,597,870km, this
means Mercury gets 9190 W/m² at 57,910,000km. Plugging these together, this
tells us that a 12.3Tw solar array of 100% efficiency in Mercury's orbit would
have a surface area of 1338 km².

Realistically, you'd at least double that, to produce the same power, as solar
panels are <50% efficient.

~~~
jnicholasp
Brilliant, thanks. So how long before we start putting solar panels in close,
direct orbit around the Sun?

~~~
guelo
Then we could beam the energy back to earth using lasers so bright that they
would burn plasma holes through our atmosphere and precisely target receiving
stations where they would vaporize water which would power a steam turbine.
Totally doable, I'd say we could get it up and running in a couple years.

~~~
jnicholasp
This sounds like sarcasm, but yes: solar collectors in close orbit around the
sun, huge flying parabolic mirrors focusing solar energy that's already 7-10x
more dense than it is at 1 AU, beaming that energy to receivers sitting in
orbit around the Earth (perhaps at Lagrange 1 and, via L4/L5, L2 to reach the
night side of the planet), relayed in to near earth orbit satellites, and
being beamed down to many surface locations at safe intensities that might
well be used to boil ocean water, driving steam turbines and producing fresh
water (and salt).

Such a system could provide energy dense power to the entire solar system
(skipping the steam turbine step for most locations, and going pure solar
electric), up to large installations for entire planets, and down to
individual spaceships.

I'm not suggesting we'll do it tomorrow. But within a hundred years, if we get
and keep our shit together..?

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vacri
> _“Saturn has a hexagon at the north pole,” said Bolton. “There is nothing on
> Jupiter that anywhere near resembles that. The largest planet in our solar
> system is truly unique. We have 36 more flybys to study just how unique it
> really is.”_

Eh? Jupiter is 'truly unique' because it _doesn 't_ have an extremely puzzling
feature that only one other planet is known to have?

~~~
tizzdogg
Why are people getting bent out of shape about the word "unique"? It is unique
because Jupiter has features that we have not observed on any other planet,
some of which are mentioned in the article (different types of storm systems,
high altitude clouds casting shadows etc). From context, he is clearly not
only talking about Saturn's hexagon. This pedantry is ridiculous.

~~~
Bjartr
People are confused. As was I at first. Considering the emphasis "truly
unique" I expected more treatment of that point by the article. By not having
that I was left feeling like I missed something / confused. People generally
don't like feeling confused.

Personally, I don't understand the people defending the usage here. As far as
I have experienced in my life, when people say "unique" in good faith they
mean "one of a kind" and those people who don't use it that way are considered
to have done a bait-and-switch.

That said, perhaps there's been a lingustic shift I haven't yet noticed.

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modzu
based on the obvious banding from the side i always assumed the top might in
fact look like a hexagon.. looking forward to seeing more!!

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Pica_soO
Where does that infrared heat orginate? Fission?

~~~
GunboatDiplomat
Probably a combination of radioactive decay and gravitational collapse.

~~~
Pica_soO
Probably another dumb question, if you would pump heat into this, and increase
the isolation factor - could you produce a brown dwarf?

~~~
nikdaheratik
The lower theoretical threshold for a brown dwarf star, which fuses
deuterium->lithium, is 13 times the mass of Jupiter. There isn't enough mass
for fusion to occur on its own no matter how energetic the particles are.

~~~
Pica_soO
Thanks.

