NASA Spacecraft Reveals Jupiter's Interior In Unprecedented Detail (theguardian.com)

NASA's Juno spacecraft has revealed that Jupiter's iconic striped bands, caused by immensely powerful winds, extend to a depth of about 3,000km below the surface. The findings also provide a partial answer to the question of whether the planet has a core, "showing that the inner 96% of the planet rotates 'as a solid body,' even though technically it is composed of an extraordinarily dense mixture of hydrogen and helium gas," reports The Guardian. From the report: The findings are published in four separate papers in the journal Nature, describing the planet's gravitational field (surprisingly asymmetrical), atmospheric flows, interior composition and polar cyclones. A crucial question was whether the bands on Jupiter, caused by air currents that are five times as strong as the most powerful hurricanes on Earth, were a "weather" phenomenon comparable to the Earth's jet streams or part of a deep-seated convection system. Juno's latest observations point to the latter, showing the jets continued to around 3,000km beneath the surface -- deep enough to cause ripples and asymmetries in the planet's gravitational field that were perceptible to detectors on the spacecraft. On Earth, the atmosphere represents about a millionth of the mass of the whole planet. The latest work suggests that on Jupiter the figure is closer to 1%. The new findings, based on extremely sensitive gravitational measurements, also begin to paint a picture of the internal structure of the planet.

Comments

Amazing

[war4peace]

These articles are among the best on Slashdot. With me not following Astronomy-related news closely, but having an interest in Astronomy, they're always very welcome and nice surprises.

JunoCAM

[backslashdot]

JunoCAM, which is a seriously downgraded camera system (there is barely a zoom on the lens), almost wasn't even included on this mission since NASA felt visual observations were unnecessary and wouldn't provide anything useful scientifically. Just imagine we could have had even better visuals than this if a larger more sophisticated camera was included. Oh well.

Re: JunoCAM

[Anonymous Coward]

3 of the 4 papers are based on results of instruments other than the Juno am, and putting a better visual camera on there would not have improved the results (including many of the pretty pictures too). There was some serious concern about guaranteeing the lifetime of the camera too due to radiation. So putting a better camera on there, which would also mean budgeting more for the use of the data, and budgeting more for hardening of that camera, would mean making cut backs on the other instruments. Other instruments like imaging spectrometers (which also produce some pretty pictures...) the gravity measurements were there to answer some current big questions about the interior composition of Jupiter, coincidentally a big part of the results in TFA.

With space probes, you can choose to get more of the same data as you've gotten before to refine previous answers to questions or to get new data to answer questions with almost no answers. The Juno design pushes much more to the latter for their given budget. The JunoCam is then a minor equipment risk without the larger budget risk involved in making it a major science instrument with better performance guarantees.

Re:JunoCAM

[CanEHdian]

And that's exactly NASA's problem. NASA needs to realize they are taxpayer-funded, and that taxpayers want to see (literally) something for their money. And you don't do that with fuzzy 1950's black-and-white pictures or pictures of the "LSD trip" kind (*cough* colour-enhanced *cough*) and certainly not with fancy graphs.

Part of the planetery missions need to be sacrificed to keep the paymasters happy. A visible-light human-visible-spectrum HD colour camera with zoom quite nicely fits that job. That's why people love Hubble. I doubt there will be much excitement among taxpayers for the pictures Webb is going to provide.

PR-wise, one human walking around on Mars is worth 100 landers on Enceladus and Europa (but a submersible probe that breaks through the ice and gets quality video footage of any life forms in the oceans will beat anything, of course).

Oblig post: Disappointed it was Jupiter's interior

[SeaFox]

I was hoping to see inside Uranus.
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OKAY! It's been posted. Sorry folks, you're too late to make the joke now.

Re:Oblig post: Disappointed it was Jupiter's inter

[MrKaos]

I was hoping to see inside Uranus. . . . . . . OKAY! It's been posted. Sorry folks, you're too late to make the joke now.

I don't know why you think that is a joke. It's called the Advanced NASA Atmospheric Lithographic Lidar Probe and it was designed to update us about the aerosols in Uranus.

Last I heard they were figuring out just how many instruments they can include to explore Uranus and the rings around it. First the rings and then and deep as they can go for as long as there is battery power remaining to keep all of the instruments going before it is crushed by the pressure of the most concentrated source of methane in the solar system. That's right, there is a lot of methane in Uranus.

If you're laughing now, you can just stop it - you're being juvenile. Exploring Uranus is a serious undertaking that many people are committed to and clever jokes about "hoping to see inside Uranus" are just unsophisticated. We're better than that here.

Scale in space is always nuts...

[vix86]

As always, the scale of things in space is always nuts, especially when talking about the Sun and Jupiter.

These winds extend nearly 3,000kms into the planet, for comparison, Earth's diameter is roughly 12,700km and Mars is ~6,000km. So the winds extend roughly a 1/4 of the Earth and basically half of mars.

Surface

[Anonymous Coward]

For general information, the surface is said (by consensus) to be the depth at which the atmospheric pressure is the same as that at sea level on Earth. There is no adjustment for gravity nor temperature. That is, it is pressure and not density. I mention this since it isn't obvious what "surface" means when applied to gas giants (or stars, for that matter - although stars have a completely different (and incompatible) definition for their "surface".)

Re:Surface

[e_pluribus_funk]

Jupiter probably almost certainly has a sizable metallic core. That core is almost certainly molten given the temperatures involved (unless there is some sort of weird convection / insulation going on).

Utter nonsense

[DerekLyons]

They do help sell the mission and the next mission to the public who are paying for it. It's probably worthwhile doing a bit less science in exchange for pretty pictures to make financing the next mission more likely.

In a world where there was ever any significant public debate on planetary missions, that would be a sensible claim. We don't live in such a world. The general public doesn't give a rats ass about space. They're not going to call their congresscritters and go "I didn't get any pretty pictures from Juno, cancel the Europa lander!". The vast majority of them probably don't even know Juno exists in the first place.