Jupiter Science |
Jupiter Science |
Dec 5 2005, 04:41 PM
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#1
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Paper: astro-ph/0512068
Date: Fri, 2 Dec 2005 20:18:41 GMT (23kb) Title: Meridional Transport in the Stratosphere of Jupiter Authors: Mao-Chang Liang (Caltech), Run-Lie Shia (Caltech), Anthony Y.-T. Lee (Caltech), Mark Allen (Caltech, JPL), A. James Friedson (JPL), and Yuk L. Yung (Caltech) Comments: 11 pages, 3 figures, 1 table. ApJL in press \\ The Cassini measurements of C$_2$H$_2$ and C$_2$H$_6$ at $\sim$5 mbar provide a constraint on meridional transport in the stratosphere of Jupiter. We performed a two-dimensional photochemical calculation coupled with mass transport due to vertical and meridional mixing. The modeled profile of C$_2$H$_2$ at latitudes less than 70$^\circ$ follows the latitude dependence of the solar insolation, while that of C$_2$H$_6$ shows little latitude dependence, consistent with the measurements. In general, our model study suggests that the meridional transport timescale above 5-10 mbar altitude level is $\gtrsim$1000 years and the time could be as short as 10 years below 10 mbar level, in order to fit the Cassini measurements. The derived meridional transport timescale above the 5 mbar level is a hundred times longer than that obtained from the spreading of gas-phase molecules deposited after the impact of Shoemaker-Levy 9 comet. There is no explanation at this time for this discrepancy. \\ ( http://arXiv.org/abs/astro-ph/0512068 , 23kb) -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Dec 7 2005, 06:58 PM
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#2
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
QUOTE (ljk4-1 @ Dec 5 2005, 08:41 AM) The derived meridional transport timescale above the 5 mbar level is a hundred times longer than that obtained from the spreading of gas-phase molecules deposited after the impact of Shoemaker-Levy 9 comet. There is no explanation at this time for this discrepancy. Everyone who is bored at the thought of Juno because it doesn't optimize eye candy may note that we're still struggling to piece together the dynamics of Jupiter. The action happens below the clouds, but it is still interesting! The subject here also happens to be the bulk of the non-solar mass in the solar system. |
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Guest_BruceMoomaw_* |
Dec 8 2005, 02:39 AM
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#3
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Guests |
"The subject here also happens to be the bulk of the non-solar mass in the solar system."
For Juno, it's also the precise composition of the bulk of the solid material in the Solar System -- far more of that went into the giant planets than into the terrestrial ones, or the Kuiper Belt and Oort Cloud. |
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Dec 8 2005, 09:56 AM
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#4
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
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Guest_BruceMoomaw_* |
Dec 9 2005, 02:04 AM
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#5
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Guests |
Isaac Asimov: "The Solar System consists of Jupiter plus debris." (Actually, I think he was a bit unfair to Saturn.)
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Dec 9 2005, 03:23 AM
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#6
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Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
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Dec 12 2005, 04:00 PM
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#7
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Paper: astro-ph/0512249
Date: Fri, 9 Dec 2005 15:38:13 GMT (232kb) Title: XMM-Newton observations of X-ray emission from Jupiter Authors: G. Branduardi-Raymont (1), A. Bhardwaj (2), R. F. Elsner (3), G. R. Gladstone (4), G. Ramsay (1), P. Rodriguez (5), R. Soria (1), J. H. Waite, Jr (6) and T. E. Cravens (7) ((1) Mullard Space Science Laboratory, University College London, Holmbury St Mary, UK, (2) Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum, India, (3) NASA Marshall Space Flight Center, Huntsville, AL, USA, (4) Southwest Research Institute, San Antonio, TX, USA, (5) XMM-Newton SOC, Madrid, Spain, (6) University of Michigan, Ann Arbor, MI, USA, (7) University of Kansas, Lawrence, KS, USA) Comments: 6 pages, 11 figures, Proceedings of the Symposium 'The X-ray Universe 2005', San Lorenzo de El Escorial, Spain, 26-30 September 2005. In press \\ We present the results of two XMM-Newton observations of Jupiter carried out in 2003 for 100 and 250 ks (or 3 and 7 planet rotations) respectively. X-ray images from the EPIC CCD cameras show prominent emission from the auroral regions in the 0.2 - 2.0 keV band: the spectra are well modelled by a combination of emission lines, including most prominently those of highly ionised oxygen (OVII and OVIII). In addition, and for the first time, XMM-Newton reveals the presence in both aurorae of a higher energy component (3 - 7 keV) which is well described by an electron bremsstrahlung spectrum. This component is found to be variable in flux and spectral shape during the Nov. 2003 observation, which corresponded to an extended period of intense solar activity. Emission from the equatorial regions of Jupiter's disk is also observed, with a spectrum consistent with that of solar X-rays scattered in the planet's upper atmosphere. Jupiter's X-rays are spectrally resolved with the RGS which clearly separates the prominent OVII contribution of the aurorae from the OVIII, FeXVII and MgXI lines, originating in the low-latitude disk regions of the planet. \\ ( http://arXiv.org/abs/astro-ph/0512249 , 232kb) -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Dec 12 2005, 07:32 PM
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#8
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Member Group: Members Posts: 295 Joined: 2-March 04 From: Central California Member No.: 45 |
QUOTE (David @ Dec 8 2005, 07:23 PM) A friend of mine insists that there are only four planets in the Solar System -- and Earth isn't one of them. Hmmm...If you get right down to it...Planets were the 'wandering' stars. There were 5 visible to those who coined the term 'planet'. Mercury, Venus, Mars, Jupiter and Saturn. I don't believe Earth was thought of as a planet for quite some time. Apparently, we still don't have a difinitive definition of the word Planet today. Eric P / MizarKey -------------------- Eric P / MizarKey
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Dec 15 2005, 04:17 PM
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#9
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Paper: astro-ph/0512359
Date: Wed, 14 Dec 2005 10:15:42 GMT (527kb) Title: Micro-arcsecond light bending by Jupiter Authors: MT Crosta and F Mignard Comments: 22 pages, 16 figures. submitted to Class. Quantum Grav \\ The detectors designed for Gaia, the next ESA space astrometry mission to be launched in 2011, will allow to observe repeatedly stars very close to Jupiter's limb. This will open a unique opportunity to test General Relativity by performing many Eddington-like experiments through the comparison between the pattern of a starfield observed with or without Jupiter. We have derived the main formulas relevant for the monopole and quadrupole light deflection by an oblate planet and developed a simulator to investigate the processing of the Gaia astrometric observation in the vicinity of the planet. The results show that such an experiment carried out with the Gaia data will provide a new fully independent determination of the PPN parameter gamma by means of differential astrometric measurements and, more importantly, for the first time will evidence the bending effect due to the quadrupole moment with a 3-sigma confidence level. Given the accuracy of the experiment for the monopole deflection, this will permit to test alternative modelling of the light bending by moving masses. \\ ( http://arXiv.org/abs/astro-ph/0512359 , 527kb) -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Jan 4 2006, 07:11 PM
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#10
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Paper: astro-ph/0601043
Date: Tue, 3 Jan 2006 12:34:14 GMT (63kb) Title: Jupiter's composition: sign of a (relatively) late formation in a chemically evolved protosolar disk Authors: Tristan Guillot (OCA), Ricardo Hueso Comments: 6 pages, 3 figures, in press in MNRAS. The definitive version is available at www.blackwellsynergy.com Proxy: ccsd ccsd-00016408 \\ It has been proposed that the enrichment in noble gases found by Galileo in Jupiter's atmosphere can be explained by their delivery inside cold planetesimals. We propose instead that this is a sign that the planet formed in a chemically evolved disk and that noble gases were acquired mostly in gaseous form during the planet's envelope capture phase. We show that the combined settling of grains to the disk midplane in the cold outer layers, the condensation of noble gases onto these grains at temperatures below 20-30K, and the evaporation from high disk altitudes effectively lead to a progressive, moderate enrichment of the disk. The fact that noble gases are vaporized from the grains in the hot inner disk regions (e.g. Jupiter formation region) is not a concern because a negative temperature gradient prevents convection from carrying the species into the evaporating region. We show that the ~2 times solar enrichment of Ar, Kr, Xe in Jupiter is hence naturally explained by a continuous growth of the planet governed by viscous diffusion in the protosolar disk in conjunction with an evaporation of the disk and its progressive enrichment on a million years timescale. \\ ( http://arXiv.org/abs/astro-ph/0601043 , 63kb) -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Feb 23 2006, 05:48 PM
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#11
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
EXO WORLDS
- Giant Planet Cores May Contain 'Electric' Rocks http://www.spacedaily.com/reports/Giant_Pl...tric_Rocks.html Minneapolis MI (SPX) Feb 20, 2006 - Researchers said their computer simulation shows rocks that exist at temperatures and pressures likely to exist at the cores of Jupiter, Saturn and giant extrasolar planets exhibit electric conductivity. The researchers - Renata Wentzcovitch and Koichiro Umemoto at the University of Minnesota, and Philip B. Allen of Stony Brook University in New York - said the model creates rocks in these environments that are considerably different from those on Earth. Astrophysics, abstract astro-ph/0602468 From: Mark S. Marley [view email] Date: Tue, 21 Feb 2006 17:45:44 GMT (316kb) Atmospheres of Extrasolar Giant Planets Authors: Mark S. Marley, Jonathan Fortney, Sara Seager, Travis Barman Comments: 16 pages, 8 figures; invited review, Protostars and Planets V (Hawai, October 2005) The key to understanding an extrasolar giant planet's spectrum--and hence its detectability and evolution--lies with its atmosphere. Now that direct observations of thermal emission from extrasolar giant planets are in hand, atmosphere models can be used to constrain atmospheric composition, thermal structure, and ultimately the formation and evolution of detected planets. We review the important physical processes that influence the atmospheric structure and evolution of extrasolar giant planets and consider what has already been learned from the first generation of observations and modeling. We pay particular attention to the roles of cloud structure, metallicity, and atmospheric chemistry in affecting detectable properties through Spitzer Space Telescope observations of the transiting giant planets. Our review stresses the uncertainties that ultimately limit our ability to interpret EGP observations. Finally we will conclude with a look to the future as characterization of multiple individual planets in a single stellar system leads to the study of comparative planetary architectures. http://arxiv.org/abs/astro-ph/0602468 -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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May 12 2006, 08:01 PM
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#12
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
-------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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May 31 2006, 08:52 PM
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#13
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Jupiter and Saturn have extended, nearly toroidal atmospheres composed of material ejected from their moons or rings.
These planets are studied to see if similar atmospheres must exist around giant extrasolar planets and might be observable in a transit of the parent star. Observation of such an atmosphere would be a marker for the presence of orbiting debris in the form of rings or moons that might otherwise be too small to be detected. http://arxiv.org/abs/astro-ph/0605655 -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Aug 10 2009, 07:21 AM
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#14
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
On arxiv today, an interesting paper on Galileo dust data from the jovian system: 2000 to 2003
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