Jupiter’s North Pole Unlike Anything Encountered in Solar System

https://www.nasa.gov/feature/jpl/jupiter-s-north-pole-unlike-anything-encountered-in-solar-system

by betolink • 10 years ago

237 87 10 years ago

numlocked• 10 years ago

"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?

lotkowskim• 10 years ago

Nope, it just takes this long for the data to travel 588 million kilometres [1]. Also the space craft will have a low powered transmitter.

[1] http://www.space.com/18383-how-far-away-is-jupiter.html

doikor• 10 years ago

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

jnicholasp4• 10 years ago

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?

hoorayimhelping• 10 years ago

Why "surely"? One of the main things about the Juno probe is how underpowered its tech is.

BurningFrog• 10 years ago

Google Fiber really needs to step up the interplanetary deployment!

dikei• 10 years ago

Imagine you need to ping google.com from mars. The round trip would be at least 40 minutes. Put a whole new meaning into the word lag.

Seriously though, the current TCP/IP protocol is not designed to deal with that kind of distance.

vvanders• 10 years ago

When I was looking into Forward Error Correction a while back all of the impressive stuff was for downlinks from remote space probes.

I don't know any specifics around the Juno probe however most of the techniques usually sent 2-3x the amount of data actually downloaded because a missed frame was 1.5hrs(43mins @ Speed of light from Earth->Jupiter). Being able to reconstruct a frame with redundant data was critical.

Combined with a low power transmitter 6mb is pretty reasonable.

jobu• 10 years ago

“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...

SilasX3• 10 years ago

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.

ngoldbaum• 10 years ago

We know basically nothing about the details of cloud structure on exoplanets.

undersuit2• 10 years ago

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...

apaprocki• 10 years ago

Some threads I read on another site described it as perturbations of a periodic wave moving around the pole in a circle.. modeled something like this:

http://www.wolframalpha.com/input/?i=plot+x%5E2+%2B+y%5E2+%3...) or http://www.wolframalpha.com/input/?i=r+%3D+1+%2B+cos(6*theta...

3pt14159• 10 years ago

Doesn't seem to hold up to a sensitivity analysis as much as one would expect given how long it has remained stable.

brianpgordon• 10 years ago

Does Saturn have an identical cloud pattern on its south pole? I always hear about the north pole, but without geographic features wouldn't there be symmetry between the north and south poles?

simcop2387• 10 years ago

Not quite, but there's definitely something strange there.

http://apod.nasa.gov/apod/ap081027.html

JohnHammersley• 10 years ago

"This is the first I've heard of Saturn's hexagon, very interesting"

Yes, me too -- thanks for posting your reply and the link, I've now learnt something new today (and it's only 00:45 so that's a good start to the weekend!).

dmreedy• 10 years ago

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• 10 years ago

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

gregwtmtno• 10 years ago

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

jl6• 10 years ago

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• 10 years ago

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

modzu• 10 years ago

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!!

jpfed• 10 years ago

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• 10 years ago

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.

vacri2• 10 years ago

“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• 10 years ago

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.

Bjartr2• 10 years ago

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.

vacri2• 10 years ago

"One of the most notable findings of these first-ever pictures of Jupiter’s north and south poles is something that the JunoCam imager did not see."

No, the article is actually saying that the lack of a hexagon is important. Combined with such insights as "some clouds are higher than other things", the mentioned items really don't add up to a breathless "truly unique". The things we already knew about Jupiter - the vibrant bands and the red dot as obvious starters - are far more interesting and worthy of a discussion about what makes the planet unique.

jessriedel• 10 years ago

It's clickbaity. People who already find a topic fascinating will skip right past it and not understand why other readers will bother to complain about clickbait.

krylon2• 10 years ago

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.)

btgeekboy2• 10 years ago

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

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

paulddraper• 10 years ago

TCP had to be revisited when Wifi became popular. Space is that x 10000.

visarga• 10 years ago

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.

Freaky• 10 years ago

http://descanso.jpl.nasa.gov/DPSummary/Juno_DESCANSO_Post121...

On the HGA we expect ≥18 kilobits per second (kbps) (≥12 kbps during Grav passes due to power required for carrier signal), and ≥10 bps on the MGA.

HGA = High Gain Antenna, MGA = Medium Gain Antenna. HGA activity is limited to when the spacecraft is precisely aligned towards Earth:

Due to the nutation of the spinning spacecraft following any maneuvers, we will need to allow several hours for nutation damping following Earth-point maneuvers before using the HGA.
Currently we allow 8 hours prior to most DSN tracks and 16 hours prior to the 6-hour MWR or Grav perijove science passes that start at PJ – 3 h.

So it's not necessarily any slower than your modem once it gets going, it just has terrible latency and dialing the connection can take the better part of a day.

Eldandan• 10 years ago

I sometimes like to scare kids by telling them about the time when I surfed the Internet with 14.4 kbit modem

You just gave me a great idea for a Halloween costume.

newscracker• 10 years ago

This is off topic for this post, but astronomy, space and space missions always have a way of putting things in perspective and showing how much humans have progressed and learned, and also the magnitude of human achievement (in the past) with what seem like completely unusable equipment today.

I look at the Voyager (1 and 2) data whenever I feel like comparing things to what we have today, and I always end up being overwhelmed by the facts, figures and what humans have achieved. I can't help but be awed.

Quoting from the Voyager FAQ [1]:

Question: How fast are the Voyager computers?
Answer:Not very fast compared to today’s standards. The master clock runs at 4 MHz but the CPU’s clock runs at only 250 KHz. A typical instruction takes 80 microseconds, that is about 8,000 instructions per second. To put this in perspective, a 2013 top-of-the-line smartphone runs at 1.5 GHz with four or more processors yielding over 14 billion instructions per second.

Quoting from the Voyager Interstellar Science page [2]:

Science data are returned to earth in real time at 160 bps.

Just imagine sending data to earth at 160 bps from a distance of 20 billion kilometers and 17 billion kilometers^ [3] , respectively, for Voyager 1 and Voyager 2. The time it takes light to travel between earth and Voyager 1 and Voyager 2 is currently about 19 hours and 15.5 hours^, respectively. (Some other communication is collected and sent at 115 kbps)

^: These figures are rounded since it doesn't make a huge difference to me at this magnitude, and also, the distance from earth to these two spacecraft does sometimes decrease due to earth's revolution around the sun.

[1] http://voyager.jpl.nasa.gov/faq.html

[2] http://voyager.jpl.nasa.gov/science/

[3] http://voyager.jpl.nasa.gov/where/

krylon2• 10 years ago

Just imagine sending data to earth at 160 bps from a distance of 20 billion kilometers and 17 billion kilometers^ [3] , respectively, for Voyager 1 and Voyager 2.

Sending data - regardless of bandwidth - over these distances is very impressive in my book. Let alone sending a computer so far and have it still work after all these years.

Pica_soO3• 10 years ago

Where does that infrared heat orginate? Fission?

GunboatDiplomat• 10 years ago

Probably a combination of radioactive decay and gravitational collapse.

Pica_soO3• 10 years ago

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

nikdaheratik2• 10 years ago

There are several sources of heat on Jupiter but the one being studied by this mission is the result of the very large magnetic field around Jupiter's generating auroras that are several times larger than the diameter of Earth.

[edit] Original statement wasn't completely accurate, as it does study the auroras, but they are generated by the planet itself. The solar wind doesn't reach the atmosphere of Jupiter.

powera• 10 years ago

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

justifier• 10 years ago

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?

Jupiter’s North Pole Unlike Anything Encountered in Solar System

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