Portal:Jupiter

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Jupiter
Cloud bands are clearly visible on Jupiter. Credit: NASA/JPL/USGS.

Jupiter is the largest planet in the Solar System and contains nearly 3/4 of all planetary matter.

With no solid surface, Jupiter is a gas and liquid filled giant. Its turbulent belts of clouds circulate parallel to the equator and often contain oval spots which are storm systems with the largest being easily twice the diameter of Earth. The great red spot has been observed for at least 300 years and rotates counter-clockwise with wind speeds of 270 miles per hour [430 km/hr].

Although observed and studied from Earth for centuries it wasn't until the mid 1970's that humans were able to get a closer look with the spacecraft Pioneer 10 and 11. The Voyager 1 and 2 spacecraft were launched with the specific purpose of collecting information and data on the Jovian worlds. In December 1995 the Galileo spacecraft entered into orbit and began it's long-term study of Jupiter and it's moons, a probe was also sent deep into the atmosphere of the gas giant.

Selected radiation astronomy

Radios

This VLA image of Jupiter doesn't look like a planetary disk at all. Credit: NRAO.

In 1955, Bernard Burke and Kenneth Franklin detected bursts of radio signals coming from Jupiter at 22.2 MHz.[1] The period of these bursts matched the rotation of the planet, and they were also able to use this information to refine the rotation rate. Radio bursts from Jupiter were found to come in two forms: long bursts (or L-bursts) lasting up to several seconds, and short bursts (or S-bursts) that had a duration of less than a hundredth of a second.[2]

Forms of decametric radio signals from Jupiter:

  • bursts (with a wavelength of tens of meters) vary with the rotation of Jupiter, and are influenced by interaction of Io with Jupiter's magnetic field.[3]
  • emission (with wavelengths measured in centimeters) was first observed by Frank Drake and Hein Hvatum in 1959.[1] The origin of this signal was from a torus-shaped belt around Jupiter's equator. This signal is caused by cyclotron radiation from electrons that are accelerated in Jupiter's magnetic field.[4]

Between September and November 23, 1963, Jupiter is detected by radar astronomy.[5]

"The dense atmosphere makes a penetration to a hard surface (if indeed one exists at all) very unlikely. In fact, the JPL results imply a correlation of the echo with Jupiter ... which corresponds to the upper (visible) atmosphere. ... Further observations will be needed to clarify the current uncertainties surrounding radar observations of Jupiter."[5]

"Although in 1963 some claimed to have detected echoes from Jupiter, these were quite weak and have not been verified by later experiments."[6]

"A search for radar echoes from Jupiter at 430 MHz during the oppositions of 1964 and 1965 failed to yield positive results, despite a sensitivity several orders of magnitude better than employed by other groups in earlier (1963) attempts at higher frequencies. ... [I]t might be suspected that meteorological disturbances of a random nature were involved, and that the echoes might be returned only in exceptional circumstances. Further support for this point of view may be gleaned from the fact that JPL found positive results for only 1 (centered at 32° System I longitude) of the 8 longitude regions investigated in 1963 (Goldstein 1964) and, in fact, had no success during their observations in 1964 (see comment by Goldstein following Dyce 1965)."[7]

"This VLA image of Jupiter [at right] doesn't look like a planetary disk at all. Most of the radio emission is synchrotron radiation from electrons in Jupiter's magnetic field."[8]

References

  1. 1.0 1.1 Linda T. Elkins-Tanton (2006). Jupiter and Saturn. New York: Chelsea House. ISBN 0-8160-5196-8. 
  2. Weintraub, Rachel A. (26 September 2005). How One Night in a Field Changed Astronomy. NASA. http://www.nasa.gov/vision/universe/solarsystem/radio_jupiter.html. Retrieved 18 February 2007. 
  3. Garcia, Leonard N. The Jovian Decametric Radio Emission. NASA. http://radiojove.gsfc.nasa.gov/library/sci_briefs/decametric.htm. Retrieved 18 February 2007. 
  4. Klein, M. J.; Gulkis, S.; Bolton, S. J. (1996). Jupiter's Synchrotron Radiation: Observed Variations Before, During and After the Impacts of Comet SL9. NASA. http://deepspace.jpl.nasa.gov/technology/TMOT_News/AUG97/jupsrado.html. Retrieved 18 February 2007. 
  5. 5.0 5.1 Gordon H. Pettengill & Irwin I. Shapiro (1965). "Radar Astronomy". Annual Review of Astronomy and Astrophysics 3: 377-410. 
  6. Irwin I. Shapiro (March 1968). "Planetary radar astronomy". Spectrum, IEEE 5 (3): 70-9. doi:10.1109/MSPEC.1968.5214821. http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5214821. Retrieved 2012-12-25. 
  7. R. B. Dyce and G. H. Pettengill, and A. D. Sanchez (August 1967). "Radar Observations of Mars and Jupiter at 70 cm". The Astronomical Journal 72 (4): 771-7. doi:10.1086/110307. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1967AJ.....72..771D&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf. Retrieved 2012-12-25. 
  8. S.G. Djorgovski (16 March 2016). A Tour of the Radio Universe. National Radio Astronomy Observatory. http://www.cv.nrao.edu/course/astr534/Tour.html. Retrieved 16 March 2014. 
Selected topic

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Selected astronomy

Aurora astronomy

This image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles. The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Credit: NASA/CXC/SWRI/G.R.Gladstone et al.
Aurora at Jupiter's north pole is seen in ultraviolet light by the Hubble Space Telescope. Credit: John T. Clarke (U. Michigan), ESA, NASA.

The "image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles."[1] The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Note that X-rays from the entire globe of Jupiter are detected.

Second is an ultraviolet image of aurora at Jupiter's north pole by the Hubble Space Telescope.

References

  1. NASA/CXC/SWRI/G.R.Gladstone (February 27, 2002). Jupiter Hot Spot Makes Trouble For Theory. Cambridge, Massachusetts: Harvard-Smithsonian Center for Astrophysics. http://chandra.harvard.edu/photo/2002/0001/. Retrieved 2012-07-11. 
Selected deity

Jupiter

Jupiter's head is crowned with laurel and ivy. Sardonyx cameo (Louvre). Credit: Jastrow.
Jupiter is in a wall painting from Pompeii, with eagle and globe. Credit: Olivierw.

A dominant line of scholarship has held that Rome lacked a body of myths in its earliest period, or that this original mythology has been irrecoverably obscured by the influence of the Greek narrative tradition.[1]

Jupiter is depicted as the twin of Juno in a statue at Praeneste that showed them nursed by Fortuna Primigenia.[2] An inscription that is also from Praeneste, however, says that Fortuna Primigenia was Jupiter's first-born child.[3] Jacqueline Champeaux sees this contradiction as the result of successive different cultural and religious phases, in which a wave of influence coming from the Hellenic world made Fortuna the daughter of Jupiter.[4] The childhood of Zeus is an important theme in Greek religion, art and literature, but there are only rare (or dubious) depictions of Jupiter as a child.[5]

References

  1. Hendrik Wagenvoort, "Characteristic Traits of Ancient Roman Religion," in Pietas: Selected Studies in Roman Religion (Brill, 1980), p. 241, ascribing the view that there was no early Roman mythology to Walter Friedrich Otto and his school.
  2. Described by Cicero, De divinatione 2.85, as cited by R. Joy Littlewood, "Fortune," in The Oxford Encyclopedia of Ancient Greece and Rome (Oxford University Press, 2010), vol. 1, p. 212.
  3. Corpus Inscriptionum Latinarum (CIL) 1.60, as cited by Littlewood, "Fortune," p. 212.
  4. J. Champeaux Fortuna. Le culte de la Fortune à Rome et dans le monde romain. I Fortuna dans la religion archaïque 1982 Rome: Publications de l'Ecole Française de Rome; as reviewed by John Scheid in Revue de l' histoire des religions 1986 203 1: pp. 67–68 (Comptes rendus).
  5. William Warde Fowler, The Roman Festivals of the Period of the Republic (London, 1908), pp. 223–225.
Selected image
Jupiter-inset.jpg

This image of Jupiter is a composite of three color images taken on Nov. 16, 2010, by NASA's Infrared Telescope Facility. Credit: NASA/JPL-Caltech/IRTF.

"This image of Jupiter is a composite of three color images taken on Nov. 16, 2010, by NASA's Infrared Telescope Facility. The particles lofted by the initial outbreak are easily identified in green as high altitude particles at the upper right, with a second outbreak to the lower left."[1]

"Earlier this year, one of Jupiter’s stripes went missing. The Southern Equatorial Band started to get lighter and paler, and eventually disappeared. Now, follow-up images from both professional and amateur astronomers are showing some activity in the area of the SEB, and scientists now believe the vanished dark stripe is making a comeback."[1]

“The reason Jupiter seemed to ‘lose’ this band – camouflaging itself among the surrounding white bands – is that the usual downwelling winds that are dry and keep the region clear of clouds died down. One of the things we were looking for in the infrared was evidence that the darker material emerging to the west of the bright spot was actually the start of clearing in the cloud deck, and that is precisely what we saw.”[2]

"This white cloud deck is made up of white ammonia ice. When the white clouds float at a higher altitude, they obscure the missing brown material, which floats at a lower altitude. Every few decades or so, the South Equatorial Belt turns completely white for perhaps one to three years, an event that has puzzled scientists for decades. This extreme change in appearance has only been seen with the South Equatorial Belt, making it unique to Jupiter and the entire solar system."[1]

"The white band wasn’t the only change on the big, gaseous planet. At the same time, Jupiter’s Great Red Spot became a darker red color."[1]

"The color of the spot – a giant storm on Jupiter that is three times the size of Earth and a century or more old – will likely brighten a bit again as the South Equatorial Belt makes its comeback."[2]

"The South Equatorial Belt underwent a slight brightening, known as a “fade,” just as NASA’s New Horizons spacecraft was flying by on its way to Pluto in 2007. Then there was a rapid “revival” of its usual dark color three to four months later. The last full fade and revival was a double-header event, starting with a fade in 1989, revival in 1990, then another fade and revival in 1993. Similar fades and revivals have been captured visually and photographically back to the early 20th century, and they are likely to be a long-term phenomenon in Jupiter’s atmosphere."[1]

References

  1. 1.0 1.1 1.2 1.3 1.4 Nancy Atkinson (24 December 2015). How Jupiter is Getting Its Belt Back. Universe Today. http://www.universetoday.com/79931/how-jupiter-is-getting-its-belt-back/. Retrieved 2017-02-12. 
  2. 2.0 2.1 Glenn Orton (24 December 2015). How Jupiter is Getting Its Belt Back. Universe Today. http://www.universetoday.com/79931/how-jupiter-is-getting-its-belt-back/. Retrieved 2017-02-12. 
Selected meteor

Clouds

NASA's Juno spacecraft was a little more than one Earth diameter from Jupiter when it captured this mind-bending, color-enhanced view of the planet's tumultuous atmosphere. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/Sean Doran.{{free media}}

"NASA's Juno spacecraft was a little more than one Earth diameter from Jupiter when it captured this mind-bending, color-enhanced view of the planet's tumultuous atmosphere."[1]

"Jupiter completely fills the image, with only a hint of the terminator (where daylight fades to night) in the upper right corner, and no visible limb (the curved edge of the planet)."[1]

"Juno took this image of colorful, turbulent clouds in Jupiter's northern hemisphere on Dec. 16, 2017 at 9:43 a.m. PST (12:43 p.m. EST) from 8,292 miles (13,345 kilometers) above the tops of Jupiter's clouds, at a latitude of 48.9 degrees."[1]

"The spatial scale in this image is 5.8 miles/pixel (9.3 kilometers/pixel)."[1]

References

  1. 1.0 1.1 1.2 1.3 Scott Bolton (16 December 2017). PIA21973: High Above Jupiter's Clouds. Pasadena, California USA: NASA/JPL. https://photojournal.jpl.nasa.gov/catalog/PIA21973. Retrieved 29 June 2018. 
Selected moon

Callisto

This image of Callisto from NASA's Galileo spacecraft, taken in May 2001, is the only complete global color image of Callisto obtained by Galileo. Credit: NASA/JPL/DLR(German Aerospace Center).

Above is a complete global color image of Callisto.

This region of Callisto shows the transition from the inner part of an enormous impact basin, Asgard, to the outer surrounding plains. Credit: NASA/JPL.

"This fascinating region [in the image at the right] of Jupiter's icy moon, Callisto, shows the transition from the inner part of an enormous impact basin, Asgard, to the outer "surrounding plains." Small, bright, fine textured, closely spaced bumps appear throughout the inner part of the basin (top of image) and create a more fine textured appearance than that seen on many of the other inter-crater plains on Callisto. At low resolution, these icy bumps make Asgard's center brighter than the surrounding terrain. What caused the bumps to form is still unknown, but they are associated clearly with the impact that formed Asgard."[1]

"The ridge that cuts diagonally across the lower left corner is one of many giant concentric rings that extend for hundreds of kilometers outside Asgard's center. Exterior to the ring (lower left corner), Callisto's surface changes significantly. Still peppered with craters, the number of icy bumps decreases while their average size increases. The fine texture is not as visible in the middle of the image. One explanation is that material from raised features (such as the ridge) may slide down slope and cover small scale features. Such images of Callisto help us understand the dynamics of giant impacts into icy surfaces, and how the large structures change with time."[1]

"North is to the top of the picture. The image, centered at 27.1 degrees north latitude and 142.3 degrees west longitude, covers an area approximately 80 kilometers (50 miles) by 90 kilometers (55 miles). The resolution is about 90 meters (295 feet) per picture element. The image was taken on September 17th, 1997 at a range of 9200 kilometers (5700 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its tenth orbit of Jupiter."[1]

References

  1. 1.0 1.1 1.2 Sue Lavoie (October 13, 1998). PIA01629: Textured Terrain in Callisto's Asgard Basin. Pasadena, California USA: NASA/JPL. http://photojournal.jpl.nasa.gov/catalog/PIA01629. Retrieved 2014-06-24. 
Selected theory

Radiative dynamos

This is a diagram of the dynamo within Jupiter producing its axisymmetric dipole magnetic field. Credit: Robert MacDowall, Planetary Magnetospheres Laboratory, Code 695, GSFC, NASA.

"The interior of Jupiter is the seat of a strong dynamo that produces a surface magnetic field in the equatorial region with an intensity of ~ 4 Gauss. This strong magnetic field and Jupiter’s fast rotation (rotation period ~ 9 h 55 min) create a unique magnetosphere in the solar system which is known for its immense size (average subsolar magnetopause distance 45-100 RJ where 1 RJ = 71492 km is the radius of Jupiter) and fast rotation [...]. Jupiter’s magnetosphere differs from most other magnetospheres in the fact that it derives much of its plasma internally from Jupiter’s moon Io. The heavy plasma, consisting principally of various charge states of S and O, inflates the magnetosphere from the combined actions of centrifugal force and thermal pressure."[1]

In "the absence of an internal heavy plasma, the dipole field would balance the average dynamic pressure of the solar wind (0.08 nPa) at a distance of ~ 42 RJ in the subsolar region [...] the observed average magnetopause location of ~ 75 RJ [...] The heavy plasma is also responsible for generating an azimuthal current exceeding 160 MA in the equatorial region of Jupiter’s magnetosphere where it is confined to a thin current sheet (half thickness ~ 2 RJ in the dawn sector)."[1]

"The energization of plasma by various electrical fields as it diffuses inwards is responsible for the creation of radiation belts in the inner magnetosphere of Jupiter. It is believed that the radial diffusion is driven by the ionospheric dynamo fields produced by winds in Jupiter’s atmosphere"[1]

"In situ and remote observations of Io and its surroundings from Voyager showed that Io is the main source of plasma in Jupiter’s magnetosphere [...] "[1]

"It is estimated that upward of 6 × 1029 amu/s (~ 1 ton/s) of plasma mass is added to the magnetosphere by Io. The picked-up plasma consists mostly of various charged states of S and O and populates a torus region extending from a radial distance of ~ 5.2 RJ to ~ 10 RJ."[1]

"The next most important source of plasma in Jupiter’s magnetosphere is the solar wind whose source strength can be estimated by a consideration of the solar wind mass flux incident on Jupiter’s magnetopause and the fractional amount that makes it into the magnetosphere (< 1%). Such a calculation suggests that the solar wind source strength is < 100 kg/s (Hill et al. 1983) considerably lower than the Io source. Nevertheless, the number density of protons (as opposed to the mass density) may be comparable to the iogenic plasma number density in the middle and outer magnetospheres where the solar wind may be able to gain access to the magnetosphere."[1]

"The escape of ions (mainly H+ and H2+ ) from the ionosphere of Jupiter provides the next significant source of plasma in Jupiter’s magnetosphere. The ionospheric plasma escapes along field lines when the gravity of Jupiter is not able to contain the hot plasma (~ 10 eV and above). The escape however is not uniform and depends on the local photoelectron density, the temperature variations of the ionosphere with the solar zenith angle, other factors such as the auroral precipitation of ions and electrons and the ionospheric heating from Pedersen currents. In situ measurements show that in Io’s torus, protons contribute to less than 20% of total ion number density and constitute < 1% of mass suggesting that the ionosphere is not a major source of plasma in Jupiter’s magnetosphere. [The] ionospheric source strength [is] in the range of ~ 20 kg/s."[1]

The "surface sputtering of the three icy satellites by jovian plasma provides the last significant source of plasma in Jupiter’s magnetosphere. Because the icy moons lack extended atmospheres and the fluxes of the incident plasma are low at the locations of these moons, the total pickup of plasma from these satellites is estimated to be less than 20 kg/s based on the plasma sputtering rates provided".[1]

"Other minor constituents found in the torus [...] were Na+ (with an abundance of < 5%) and molecular ions SO+ and SO2+ (both with abundances of < 1% of the total). The average mass of a torus ion is ~ 20 and the average fractional charge on an ion is ~ 1.2 [...]. The bulk velocity of the plasma was found to be ~ 75 km/s, close to the corotational value."[1]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Krishan K. Khurana; Margaret G. Kivelson; Vytenis M. Vasyliunas; Norbert Krupp; Joachim Woch; Andreas Lagg; Barry H. Mauk; William S. Kurth (2004). Bagenal, F.. ed. The Configuration of Jupiter’s Magnetosphere, In: Jupiter: The Planet, Satellites and Magnetosphere. Cambridge University Press. pp. 24. ISBN 0-521-81808-7. http://www.igpp.ucla.edu/people/mkivelson/Publications/279-Ch24.pdf. Retrieved 2014-03-29.