APOD: Orbiting Jupiter (2017 Jun 07)

[APOD Robot]

Orbiting Jupiter

Explanation: What would it be like to orbit Jupiter? The dramatic featured video depicts just this and was made from images taken by NASA's Juno spacecraft currently orbiting the Jovian giant. Juno recently completed its sixth pass near Jupiter during its looping elliptical six-week orbit. As the time-lapse video starts, alternating dark and light cloud bands passed underneath the spacecraft as it approaches Jupiter's South Pole. These clouds contain complex textures involving eddies, swirls, ovals, and extended clouds that are have no direct analog from Earth. As the spacecraft passes beneath Jupiter, new cloud patterns devoid of long bands emerge but are again rich with alien swirls and ovals. Over the next few years, Juno will continue to orbit and probe Jupiter, determine atmospheric water abundance, and attempt to determine if Jupiter has a solid surface underneath these fascinating clouds.

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[Nitpicker]

Magnificent! Thank you.

[RocketRon]

Certainly is a strange place, or 'weather' patterns at least....

and attempt to determine if Jupiter has a solid surface underneath these fascinating clouds.

What has bouncing a radar beam determined ?
Or have the Jovians countered that by jamming it ?? ??

[Coil_Smoke]

I figure there must be transition zones where Jupiter's atmosphere is compressed into a liquid phase then solid phase below that. If no terrestrial materials are found to be part of Jupiter's make up, what about Metallic Hydrogen as a candidate for a solid surface below all that circulation and turbulence ? There is something down there. I was surprised by persistent 'Bruises' left from comet impacts. Something below the clouds kept those wounds from simply blowing away.

[ygmarchi]

Before Juno I was not aware that even our visual knowledge of Jupiter was quite approximate and superficial.

[ta152h0]

" How low can yo go " as the bar is being lowered, to the Limbo Beat

[E Fish]

Maybe it'll be a giant diamond like Arthur C. Clarke wrote in 2061. It was based on a hypothesis by some astronomers, but I always found the idea fascinating.

[Chris Peterson]

I figure there must be transition zones where Jupiter's atmosphere is compressed into a liquid phase then solid phase below that. If no terrestrial materials are found to be part of Jupiter's make up, what about Metallic Hydrogen as a candidate for a solid surface below all that circulation and turbulence ? There is something down there. I was surprised by persistent 'Bruises' left from comet impacts. Something below the clouds kept those wounds from simply blowing away.

I don't believe there is any need to invoke some sort of solid surface below the clouds to explain the persistence of atmospheric disturbances caused by impacts. It can simply be a matter of scale and the fact that the atmospheric flow is substantially laminar over large areas.

[Donald Pelletier]

Over the next few years ????, Juno will continue to orbit and probe Jupiter, determine atmospheric water abundance, and attempt to determine if Jupiter has a solid surface underneath these fascinating clouds.
"Over the next few months" will be more appropriate i think because Juno is schedule to crash into Jupiter's atmosphere on october 2017 (https://en.wikipedia.org/wiki/Juno_(spa ... ntegration)

[Chris Peterson]

Over the next few years ????, Juno will continue to orbit and probe Jupiter, determine atmospheric water abundance, and attempt to determine if Jupiter has a solid surface underneath these fascinating clouds.
"Over the next few months" will be more appropriate i think because Juno is schedule to crash into Jupiter's atmosphere on october 2017 (https://en.wikipedia.org/wiki/Juno_(spa ... ntegration)

Juno will proceed through a series of close encounters over the next year (into July 2018), at which point the future of the mission will be re-evaluated. If the spacecraft remains healthy, the mission could be extended.

[danhammang]

Wanted to thank Eichstadt and Doran for making this video available to all of us. It's hard to describe my response...words like jaw dropping come to mind. Perhaps a deep sense of wonder, wonder at this world around us, wonder at the technology that is on display, and wonder at the generosity of folks willing to make it available to us. This is really great. Thanks to everybody who made it possible.

[Mulsar11]

Everything you see in the video is AMAZING! One of the amazing things is toward the end. In one of the bands of "clouds" is a series of white "storms", that look almost equally space one after the other and of almost equal size going up to the top of the frame. This is very curious to me to see this detailed repeatability unless there is some physical structure/process that disturbs the otherwise semi chaotic flow of the "weather" on Jupiter. Anybody have any thoughts?

[Chris Peterson]

Everything you see in the video is AMAZING! One of the amazing things is toward the end. In one of the bands of "clouds" is a series of white "storms", that look almost equally space one after the other and of almost equal size going up to the top of the frame. This is very curious to me to see this detailed repeatability unless there is some physical structure/process that disturbs the otherwise semi chaotic flow of the "weather" on Jupiter. Anybody have any thoughts?

Chaotic does not imply any lack of structure. Indeed, a high degree of structure and chaotic behavior often go hand-in-hand.

[SeedsofEarth]

I must ask you, why do we see no cloud movement during this pass? Surely the Juno craft is not moving as fast as the video implies. It would not take it six weeks to complete an orbit if that were the case, would it? I really expected to see the clouds moving around, swirling and sweeping across the planet as they do on older videos sent back from other crafts approachiong and passing by Jipiter? In this video, the clouds appear to be static, as if the planet were merely a plastic globe with a photograph of Jupiter superimposed over it.

[Chris Peterson]

I must ask you, why do we see no cloud movement during this pass? Surely the Juno craft is not moving as fast as the video implies. It would not take it six weeks to complete an orbit if that were the case, would it? I really expected to see the clouds moving around, swirling and sweeping across the planet as they do on older videos sent back from other crafts approachiong and passing by Jipiter? In this video, the clouds appear to be static, as if the planet were merely a plastic globe with a photograph of Jupiter superimposed over it.

I think these images (about 15, it looks like) were taken over a span of just a few hours. I don't know the details of the processing, but they were either morphed together in some fashion or digitally mapped onto a sphere and the view path modeled. In any case, the time period is too short for us to see significant movement within the belts.

[Whiskybreath]

Magnificent! Thank you.

I really can't think of more to say than that. Outstanding.

[othermoons]

Relative to Earth, Jupiter is much further away therefore much colder yet the core temperature is much much hotter. The dense clouds totally and ominously cover the surface; however, is there a chance that the surface area may not be as hot as we thought?

[Chris Peterson]

Relative to Earth, Jupiter is much further away therefore much colder yet the core temperature is much much hotter. The dense clouds totally and ominously cover the surface; however, is there a chance that the surface area may not be as hot as we thought?

The interior temperature of the planets is largely unrelated to the distance from the Sun. Interior temperature is determined by residual heat of formation and by radioactive decay.

I would not place much confidence in any estimates of temperatures below the cloud tops, given the poor understanding of Jupiter's interior and uncertainty about the quality of models.

[neufer]

Relative to Earth, Jupiter is much further away therefore much colder yet the core temperature is much much hotter. The dense clouds totally and ominously cover the surface; however, is there a chance that the surface area may not be as hot as we thought?

The interior temperature of the planets is largely unrelated to the distance from the Sun. Interior temperature is determined by residual heat of formation and by radioactive decay.

<<Saturn has a hot interior, reaching 11,700 °C at its core, and it radiates 2.5 times more energy into space than it receives from the Sun. Jupiter's thermal energy is generated by the Kelvin–Helmholtz mechanism of slow gravitational compression, but this alone may not be sufficient to explain heat production for Saturn, because it is less massive. An alternative or additional mechanism may be generation of heat through the "raining out" of droplets of helium deep in Saturn's interior. As the droplets descend through the lower-density hydrogen, the process releases heat by friction and leaves Saturn's outer layers depleted of helium. These descending droplets may have accumulated into a helium shell surrounding the core.>>

<<Uranus only radiates 1.1 times as much energy as it receives from the Sun; whereas Neptune radiates about 2.61 times as much energy as it receives from the Sun. Neptune is the farthest planet from the Sun, yet its internal energy is sufficient to drive the fastest planetary winds seen in the Solar System. Depending on the thermal properties of its interior, the heat left over from Neptune's formation may be sufficient to explain its current heat flow, though it is more difficult to simultaneously explain Uranus's lack of internal heat while preserving the apparent similarity between the two planets.

Note: At a depth of 7,000 km, the conditions may be such that methane decomposes into diamond crystals that rain downwards like hailstones. Very-high-pressure experiments at the Lawrence Livermore National Laboratory suggest that the base of the mantle may be an ocean of liquid carbon with floating solid 'diamonds'.>>

[Nitpicker]

I don't believe there is any need to invoke some sort of solid surface below the clouds to explain the persistence of atmospheric disturbances caused by impacts. It can simply be a matter of scale and the fact that the atmospheric flow is substantially laminar over large areas.

I don't think laminar is the correct word here. The flow in the Jovian atmosphere is highly turbulent.

[Chris Peterson]

I don't believe there is any need to invoke some sort of solid surface below the clouds to explain the persistence of atmospheric disturbances caused by impacts. It can simply be a matter of scale and the fact that the atmospheric flow is substantially laminar over large areas.

I don't think laminar is the correct word here. The flow in the Jovian atmosphere is highly turbulent.

It's also highly laminar- certainly across latitudes, and probably with height, as well. There is turbulence in places (particularly across boundaries), but large scale structure is not destroyed, because the turbulence is local.

[thburleson]

What is the source of the minor pointing angle oscillation seen in the video? Is this spacecraft related, or perhaps a post processing artifact?

[Nitpicker]

I don't believe there is any need to invoke some sort of solid surface below the clouds to explain the persistence of atmospheric disturbances caused by impacts. It can simply be a matter of scale and the fact that the atmospheric flow is substantially laminar over large areas.

I don't think laminar is the correct word here. The flow in the Jovian atmosphere is highly turbulent.

It's also highly laminar- certainly across latitudes, and probably with height, as well. There is turbulence in places (particularly across boundaries), but large scale structure is not destroyed, because the turbulence is local.

Technically, it is not highly laminar, but less turbulent. The technical basis for determining whether flow is laminar or turbulent is Reynolds number (Re), and the Re values characterizing the flows in the visible cloud formations, are too high to be considered laminar. But there is certainly a wide range in the degree of turbulence. I may be arguing a technical point, but laminar flow is fairly unusual and requires small scales and/or low velocities and/or high viscosities.

[Chris Peterson]

I don't think laminar is the correct word here. The flow in the Jovian atmosphere is highly turbulent.

It's also highly laminar- certainly across latitudes, and probably with height, as well. There is turbulence in places (particularly across boundaries), but large scale structure is not destroyed, because the turbulence is local.

Technically, it is not highly laminar, but less turbulent. The technical basis for determining whether flow is laminar or turbulent is Reynolds number (Re), and the Re values characterizing the flows in the visible cloud formations, are too high to be considered laminar. But there is certainly a wide range in the degree of turbulence. I may be arguing a technical point, but laminar flow is fairly unusual and requires small scales and/or low velocities and/or high viscosities.

True, I do not know the Reynolds number for any part of the Jovian atmosphere, or indeed, if anybody does. So I can't say the flow is technically laminar. However, when looking at time lapse imagery of the differential motion within the atmosphere, it certainly gives that impression.

Suffice to say, large regions of the atmosphere are either not turbulent, or exhibit very low turbulence.

[neufer]

The flow in the Jovian atmosphere is highly turbulent.

It's also highly laminar- certainly across latitudes, and probably with height, as well. There is turbulence in places (particularly across boundaries), but large scale structure is not destroyed, because the turbulence is local.

Technically, it is not highly laminar, but less turbulent. The technical basis for determining whether flow is laminar or turbulent is Reynolds number (Re), and the Re values characterizing the flows in the visible cloud formations, are too high to be considered laminar. But there is certainly a wide range in the degree of turbulence. I may be arguing a technical point, but laminar flow is fairly unusual and requires small scales and/or low velocities and/or high viscosities.

The quasi-laminar flow has more to do with a low Rossby number (Ro) than with a low Reynolds number (Re).

<<The Rossby number (Ro) named for Carl-Gustav Arvid Rossby, is a dimensionless number used in describing fluid flow. The Rossby number is the ratio of inertial force to Coriolis force. It is commonly used in geophysical phenomena in the oceans and atmosphere, where it characterizes the importance of Coriolis accelerations arising from planetary rotation.

The Rossby number (Ro) is defined as:

---

where U and L are, respectively, characteristic velocity and length scales of the phenomenon and f = 2 Ω sin φ is the Coriolis frequency, where Ω is the angular frequency of planetary rotation and φ the latitude.

A small Rossby number signifies a system which is strongly affected by Coriolis forces, and a large Rossby number signifies a system in which inertial and centrifugal forces dominate.>>