Jupiter Science Options

[ljk4-1]

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)

[JRehling]

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.

[Guest_BruceMoomaw_*]

"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.

[AndyG]

The subject here also happens to be the bulk of the non-solar mass in the solar system.

Yes! Worth remembering:

All terrestrial planets, moons and asteroids are 0.5% by mass of the solar system's orbiting material.

Jupiter: >71%

Andy G

[Guest_BruceMoomaw_*]

Isaac Asimov: "The Solar System consists of Jupiter plus debris." (Actually, I think he was a bit unfair to Saturn.)

[David]

Isaac Asimov: "The Solar System consists of Jupiter plus debris."  (Actually, I think he was a bit unfair to Saturn.)

A friend of mine insists that there are only four planets in the Solar System -- and Earth isn't one of them.

[ljk4-1]

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)

[MizarKey]

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

[ljk4-1]

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)

[ljk4-1]

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)

[ljk4-1]

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

[ljk4-1]

X-Ray Emission from Jupiter, Saturn, and Earth: A Short Review

http://arXiv.org/abs/astro-ph/0605282

[ljk4-1]

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

[Paolo]

On arxiv today, an interesting paper on Galileo dust data from the jovian system: 2000 to 2003