Page 2 of 2
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Thu Jun 08, 2017 2:07 am
by André Léveillé
Etourdissant! stunning! You want to watch it again and again in loop...
It it conceivable to put an observation satellite on a more stable orbit like an geostationary orbit? Or on a Lagrange point on one of Jupiter moons?
Will it need too much energy to compensate for the interaction of Jupiter satellites?
I want my flying saucer to go there...
Tnx for sharing
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Thu Jun 08, 2017 3:00 am
by Nitpicker
Thank you Art. The large-scale band structures in the clouds of Jupiter (presumably formed by Hadley-like cell rotation, due to the dominance of Coriolis forces on Jupiter) set the limits on the largest turbulent eddies and swirls that appear to form. I assume, now, that the banded structure is what Chris was referring to, when describing laminar flows, and what you (Art) refer to when describing quasi-laminar flows. Fair enough.
Within each band, the Reynolds number should be indicative of the smallest sizes of the eddies that form. Higher Re should indicate a greater range of eddy sizes, up to the size of the band or cell. We probably don't have sufficient resolution to see the smallest eddies, but they are everywhere visible in this APOD. Where there are eddies, there is turbulence.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 2:05 am
by jbelfiore
Hello. What are the approximately equally spaced horizontal black dots at the top and the bottom of the video? Are they moons of Jupiter? (and if so, do you know which moons?) Thank you so much. (This is a fantastic video - beautiful!!!)
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 3:43 am
by Coil_Smoke
When In Doubt...' QUASI '
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 4:31 am
by Nitpicker
jbelfiore wrote:Hello. What are the approximately equally spaced horizontal black dots at the top and the bottom of the video? Are they moons of Jupiter? (and if so, do you know which moons?) Thank you so much. (This is a fantastic video - beautiful!!!)
There are no (known) small moons that close to Jupiter and on such inclined orbits. The dots are probably some form of fiducial marker from the JunoCam.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 5:57 pm
by Mickey Mouse
Sometimes a super-sharpened video is not realistic.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 10:23 pm
by owlice
The five white spots at the top/top right here (screenshot from the video) appear to be pretty evenly spaced. Are these impact scars?
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Fri Jun 09, 2017 10:30 pm
by Chris Peterson
owlice wrote:The five white spots at the top/top right here (screenshot from the video) appear to be pretty evenly spaced. Are these impact scars?
juno.JPG
No. They are much too far apart (and they've been there for decades). They're semi-stable storm systems.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 2:16 am
by owlice
Thank you, Chris.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 4:15 am
by BDanielMayfield
Chris Peterson wrote:They're semi-stable storm systems.
Vast areas of Jupiter must have what we would view as very monotonous weather. The forecast for the next century is stormy, with whiteout conditions ... the same as last century.
Bruce
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 6:03 am
by Nitpicker
Though the storm systems do drift in longitude by amounts that are not always easy to predict from month to month and season to season.
But yes, a typical weather forecast might be: dreadful with a high chance of death.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 8:41 am
by BDanielMayfield
I wonder, at what barometric pressure range are Jupiter's cloud tops? (In case we want to build a floating station inside the Jovian atmosphere.)
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 9:51 am
by Nitpicker
BDanielMayfield wrote:I wonder, at what barometric pressure range are Jupiter's cloud tops? (In case we want to build a floating station inside the Jovian atmosphere.)
It is roughly 1 bar at the top of the clouds and about 10 bars some 90 km below.
Re: APOD: Orbiting Jupiter (2017 Jun 07)
Posted: Sat Jun 10, 2017 11:37 am
by neufer
https://www2.jpl.nasa.gov/adv_tech/balloons/outer_jupisat.htm wrote:
Balloons Technology for Jupiter and Saturn
<<Solar Infrared Mongolfiere Aerobots (SIRMAs) use a combination to lower planetary infrared heating during the night and solar heating during the day. A detailed study performed on the use of SIRMA-type balloons at Jupiter indicates that about 112 kg of total floating mass would be required to support a ten-kg payload. The balloon would float at about 10,000 Pa [
the cold 50 km tropopause level] during the day and descends to about 20,000 Pa at night, using isentropic compression heating to help slow the nightly descent rate. The total delivered mass would be about ten times lighter than for comparable pure hydrogen balloon systems at Jupiter. A similar SIRMA for Saturn would weigh about 220 kg and may also be viable. SIRMAs for Uranus and Neptune, however, are less mass-competitive than ambient gas balloons that are filled with low molecular weight gas from these planets upper atmospheres. In order to obtain data from the lower atmosphere regions of Jupiter and Saturn, it appears quite feasible to drop lightweight, deep atmosphere sondes from the balloon as it passes over areas of scientific interest. Results can then be relayed to the stratosphere-floating Montgolfiere.>>
Nitpicker wrote:BDanielMayfield wrote:
I wonder, at what barometric pressure range are Jupiter's cloud tops?
(In case we want to build a floating station inside the Jovian atmosphere.)
It is roughly 1 bar at the top of the clouds and about 10 bars some 90 km below.
