Physical_characteristics Jupiter

1 physical characteristics

1.1 composition
1.2 mass , size
1.3 internal structure
1.4 atmosphere

1.4.1 cloud layers
1.4.2 great red spot , other vortices


1.5 magnetosphere

physical characteristics

jupiter composed of gaseous , liquid matter. largest of 4 giant planets in solar system , hence largest planet. has diameter of 142,984 km (88,846 mi) @ equator. average density of jupiter, 1.326 g/cm, second highest of giant planets, lower of 4 terrestrial planets.

composition

jupiter s upper atmosphere 88–92% hydrogen , 8–12% helium percent volume of gas molecules. helium atom has 4 times mass hydrogen atom, composition changes when described proportion of mass contributed different atoms. thus, jupiter s atmosphere approximately 75% hydrogen , 24% helium mass, remaining 1 percent of mass consisting of other elements. atmosphere contains trace amounts of methane, water vapor, ammonia, , silicon-based compounds. there traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, , sulfur. outermost layer of atmosphere contains crystals of frozen ammonia. interior contains denser materials - mass 71% hydrogen, 24% helium, , 5% other elements. through infrared , ultraviolet measurements, trace amounts of benzene , other hydrocarbons have been found.

the atmospheric proportions of hydrogen , helium close theoretical composition of primordial solar nebula. neon in upper atmosphere consists of 20 parts per million mass, tenth abundant in sun. helium depleted 80% of sun s helium composition. depletion result of precipitation of these elements interior of planet.

based on spectroscopy, saturn thought similar in composition jupiter, other giant planets uranus , neptune have relatively less hydrogen , helium , relatively more ices , termed ice giants.

mass , size


jupiter s diameter 1 order of magnitude smaller (×0.10045) of sun, , 1 order of magnitude larger (×10.9733) of earth. great red spot same size earth.

jupiter s mass 2.5 times of other planets in solar system combined—this massive barycenter sun lies above sun s surface @ 1.068 solar radii sun s center. jupiter larger earth , considerably less dense: volume of 1,321 earths, 318 times massive. jupiter s radius 1/10 radius of sun, , mass 0.001 times mass of sun, densities of 2 bodies similar. jupiter mass (mj or mjup) used unit describe masses of other objects, particularly extrasolar planets , brown dwarfs. so, example, extrasolar planet hd 209458 b has mass of 0.69 mj, while kappa andromedae b has mass of 12.8 mj.

theoretical models indicate if jupiter had more mass @ present, shrink. small changes in mass, radius not change appreciably, , above 500 m⊕ (1.6 jupiter masses) interior become more compressed under increased pressure volume decrease despite increasing amount of matter. result, jupiter thought have large diameter planet of composition , evolutionary history can achieve. process of further shrinkage increasing mass continue until appreciable stellar ignition achieved, in high-mass brown dwarfs having around 50 jupiter masses.

although jupiter need 75 times massive fuse hydrogen , become star, smallest red dwarf 30 percent larger in radius jupiter. despite this, jupiter still radiates more heat receives sun; amount of heat produced inside similar total solar radiation receives. additional heat generated kelvin–helmholtz mechanism through contraction. process causes jupiter shrink 2 cm each year. when first formed, jupiter hotter , twice current diameter.

internal structure

jupiter thought consist of dense core mixture of elements, surrounding layer of liquid metallic hydrogen helium, , outer layer predominantly of molecular hydrogen. beyond basic outline, there still considerable uncertainty. core described rocky, detailed composition unknown, properties of materials @ temperatures , pressures of depths (see below). in 1997, existence of core suggested gravitational measurements, indicating mass of 12 45 times of earth, or 4%–14% of total mass of jupiter. presence of core during @ least part of jupiter s history suggested models of planetary formation require formation of rocky or icy core massive enough collect bulk of hydrogen , helium protosolar nebula. assuming did exist, may have shrunk convection currents of hot liquid metallic hydrogen mixed molten core , carried contents higher levels in planetary interior. core may entirely absent, gravitational measurements not yet precise enough rule possibility out entirely.

animation of jupiter seen in infrared

the uncertainty of models tied error margin in hitherto measured parameters: 1 of rotational coefficients (j6) used describe planet s gravitational moment, jupiter s equatorial radius, , temperature @ 1 bar pressure. juno mission, arrived in july 2016, expected further constrain values of these parameters better models of core.

the core region may surrounded dense metallic hydrogen, extends outward 78% of radius of planet. rain-like droplets of helium , neon precipitate downward through layer, depleting abundance of these elements in upper atmosphere. rainfalls of diamonds have been suggested occur on jupiter, on saturn , ice giants uranus , neptune.

above layer of metallic hydrogen lies transparent interior atmosphere of hydrogen. @ depth, pressure , temperature above hydrogen s critical pressure of 1.2858 mpa , critical temperature of 32.938 k. in state, there no distinct liquid , gas phases—hydrogen said in supercritical fluid state. convenient treat hydrogen gas in upper layer extending downward cloud layer depth of 1,000 km, , liquid in deeper layers. physically, there no clear boundary—the gas smoothly becomes hotter , denser 1 descends.

the temperature , pressure inside jupiter increase steadily toward core, due kelvin–helmholtz mechanism. @ pressure level of 10 bars (1 mpa), temperature around 340 k (67 °c; 152 °f). @ phase transition region hydrogen—heated beyond critical point—becomes metallic, calculated temperature 10,000 k (9,700 °c; 17,500 °f) , pressure 200 gpa. temperature @ core boundary estimated 36,000 k (35,700 °c; 64,300 °f) , interior pressure 3,000–4,500 gpa.

this cut-away illustrates model of interior of jupiter, rocky core overlaid deep layer of liquid metallic hydrogen.



atmosphere

jupiter has largest planetary atmosphere in solar system, spanning on 5,000 km (3,000 mi) in altitude. because jupiter has no surface, base of atmosphere considered point @ atmospheric pressure equal 100 kpa (1.0 bar).

cloud layers

the movement of jupiter s counter-rotating cloud bands. looping animation maps planet s exterior onto cylindrical projection.

jupiter perpetually covered clouds composed of ammonia crystals , possibly ammonium hydrosulfide. clouds located in tropopause , arranged bands of different latitudes, known tropical regions. these sub-divided lighter-hued zones , darker belts. interactions of these conflicting circulation patterns cause storms , turbulence. wind speeds of 100 m/s (360 km/h) common in zonal jets. zones have been observed vary in width, color , intensity year year, have remained sufficiently stable scientists give them identifying designations.

the cloud layer 50 km (31 mi) deep, , consists of @ least 2 decks of clouds: thick lower deck , thin clearer region. there may thin layer of water clouds underlying ammonia layer. supporting idea of water clouds flashes of lightning detected in atmosphere of jupiter. these electrical discharges can thousand times powerful lightning on earth. water clouds assumed generate thunderstorms in same way terrestrial thunderstorms, driven heat rising interior.

the orange , brown coloration in clouds of jupiter caused upwelling compounds change color when exposed ultraviolet light sun. exact makeup remains uncertain, substances thought phosphorus, sulfur or possibly hydrocarbons. these colorful compounds, known chromophores, mix warmer, lower deck of clouds. zones formed when rising convection cells form crystallizing ammonia masks out these lower clouds view.

jupiter s low axial tilt means poles receive less solar radiation @ planet s equatorial region. convection within interior of planet transports more energy poles, balancing out temperatures @ cloud layer.

great red spot , other vortices

time-lapse sequence approach of voyager 1, showing motion of atmospheric bands , circulation of great red spot. recorded on 32 days 1 photograph taken every 10 hours (once per jovian day). see full size video.

the best known feature of jupiter great red spot, persistent anticyclonic storm larger earth, located 22° south of equator. known have been in existence since @ least 1831, , possibly since 1665. images hubble space telescope have shown many 2 red spots adjacent great red spot. storm large enough visible through earth-based telescopes aperture of 12 cm or larger. oval object rotates counterclockwise, period of 6 days. maximum altitude of storm 8 km (5 mi) above surrounding cloudtops.

great red spot decreasing in size (may 15, 2014).

the great red spot large enough accommodate earth within boundaries. mathematical models suggest storm stable , may permanent feature of planet. however, has decreased in size since discovery. initial observations in late 1800s showed approximately 41,000 km (25,500 mi) across. time of voyager flybys in 1979, storm had length of 23,300 km (14,500 mi) , width of approximately 13,000 km (8,000 mi). hubble observations in 1995 showed had decreased in size again 20,950 km (13,020 mi), , observations in 2009 showed size 17,910 km (11,130 mi). of 2015, storm measured @ approximately 16,500 10,940 km (10,250 6,800 mi), , decreasing in length 930 km (580 mi) per year.

storms such common within turbulent atmospheres of giant planets. jupiter has white ovals , brown ovals, lesser unnamed storms. white ovals tend consist of relatively cool clouds within upper atmosphere. brown ovals warmer , located within normal cloud layer . such storms can last little few hours or stretch on centuries.

even before voyager proved feature storm, there strong evidence spot not associated deeper feature on planet s surface, spot rotates differentially respect rest of atmosphere, faster , more slowly.

in 2000, atmospheric feature formed in southern hemisphere similar in appearance great red spot, smaller. created when several smaller, white oval-shaped storms merged form single feature—these 3 smaller white ovals first observed in 1938. merged feature named oval ba, , has been nicknamed red spot junior. has since increased in intensity , changed color white red.

in april 2017, scientists reported discovery of great cold spot in jupiter s thermosphere @ north pole 24,000 km (15,000 mi) across, 12,000 km (7,500 mi) wide, , 200 °c (360 °f) cooler surrounding material. feature discovered researchers @ large telescope in chile, searched archived data nasa infrared telescope facility between 1995 , 2000. found that, while spot changes size, shape , intensity on short term, has maintained general position in atmosphere across more 15 years of available data. scientists believe spot giant vortex similar great red spot , appears quasi-stable vortices in earth s thermosphere. interactions between charged particles generated io , planet s strong magnetic field resulted in redistribution of heat flow, forming spot.

magnetosphere


aurorae on north pole of jupiter viewed hubble



infrared view of jupiter s southern lights, taken jovian infrared auroral mapper

jupiter s magnetic field fourteen times strong of earth, ranging 4.2 gauss (0.42 mt) @ equator 10–14 gauss (1.0–1.4 mt) @ poles, making strongest in solar system (except sunspots). field thought generated eddy currents—swirling movements of conducting materials—within liquid metallic hydrogen core. volcanoes on moon io emit large amounts of sulfur dioxide forming gas torus along moon s orbit. gas ionized in magnetosphere producing sulfur , oxygen ions. they, hydrogen ions originating atmosphere of jupiter, form plasma sheet in jupiter s equatorial plane. plasma in sheet co-rotates planet causing deformation of dipole magnetic field of magnetodisk. electrons within plasma sheet generate strong radio signature produces bursts in range of 0.6–30 mhz.

at 75 jupiter radii planet, interaction of magnetosphere solar wind generates bow shock. surrounding jupiter s magnetosphere magnetopause, located @ inner edge of magnetosheath—a region between , bow shock. solar wind interacts these regions, elongating magnetosphere on jupiter s lee side , extending outward until reaches orbit of saturn. 4 largest moons of jupiter orbit within magnetosphere, protects them solar wind.

the magnetosphere of jupiter responsible intense episodes of radio emission planet s polar regions. volcanic activity on jupiter s moon io (see below) injects gas jupiter s magnetosphere, producing torus of particles planet. io moves through torus, interaction generates alfvén waves carry ionized matter polar regions of jupiter. result, radio waves generated through cyclotron maser mechanism, , energy transmitted out along cone-shaped surface. when earth intersects cone, radio emissions jupiter can exceed solar radio output.