Solar System, technical/Saturn

The 6th planet Saturn is first recorded around 1610 by Galileo and is most widely recognised by it's icy rings. It has an atmosphere which is rich in both Hydrogen and Helium. Over 24 moons and satellite bodies orbit the planet of which Titan is the largest with an atmospheric pressure on the surface 50% greater than that on Earth.

Saturn in natural color during its equinox is imaged by the Cassini orbiter. Credit: NASA/JPL/Space Science Institute.

Physical Features edit

With an average density lower than water Saturn is unlikely to contain any solid surface under it's hazy exterior.

  • Rings
    • C ring - Innermost ring, dark in colour. Also called the Crepe ring.
    • B ring - Between the C ring and Cassini's division.
    • A ring - The large ring between the Cassini division and the Enke division
    • G ring - Outermost ring, quite thin.

The gaps between the rings are formed in some cases due to resonances with moons or confined by shepherd satellites which gravitationally tug straying particles back into the rings. There are not enough moons to fully account for all the ringlets hence it is believed that gravitational / spiral waves are to account for them (akin to the spiral density waves in galaxies).

Exploration edit

Studied briefly by a Pioneer mission it has been much more extensively studied by the Cassini mission since the spacecraft arrived in 2004.

Statistics edit

  • Average distance from sun: 9.5388 AU (14.27 x 10^8km)
  • Average orbital velocity: 9.64 km/s
  • Orbital period: 29.461 years (10,760 days)
  • Rotation period: 10h 39m 25s
  • Average density: 0.69 g/cm^3
  • Gravity at base of clouds: 1.16 G
  • Temperature at cloud tops: -180 C (-292 F)

Meteor astronomy edit

 
A global storm girdles Saturn in 2011. The head of the storm (bright area) passes the tail circling around the left limb. Credit: NASA/JPL-Caltech/SSI.
 
North polar hexagonal cloud feature, discovered by Voyager 1 and confirmed in 2006 by Cassini is shown. Credit: NASA / JPL-Caltech / Space Science Institute.
 
This is a closer view of the north polar vortex at the center of the hexagon. Credit: NASA / JPL-Caltech / Space Science Institute.
 
Saturn's atmosphere and its rings are shown here in a false color composite made from Cassini images taken in near infrared light through filters that sense different amounts of methane gas. Credit: NASA/JPL/Space Science Institute.

"The upper clouds are composed of ammonia crystals"[1]

"In 1990, the Hubble Space Telescope imaged an enormous white cloud near Saturn's equator that was not present during the Voyager encounters and in 1994, another, smaller storm was observed. The 1990 storm was an example of a Great White Spot, a unique but short-lived phenomenon that occurs once every Saturnian year, roughly every 30 Earth years, around the time of the northern hemisphere's summer solstice.[2] Previous Great White Spots were observed in 1876, 1903, 1933 and 1960, with the 1933 storm being the most famous. If the periodicity is maintained, another storm will occur in about 2020.[3]"[4]

"Wind speeds on Saturn can reach 1,800 km/h (1,100 mph) ... Voyager data indicate peak easterly winds of 500 m/s (1800 km/h).[5]"[4]

"Infrared imaging has shown that Saturn's south pole has a warm polar vortex, the only known example of such a phenomenon in the Solar System.[6] Whereas temperatures on Saturn are normally −185 °C, temperatures on the vortex often reach as high as −122 °C, believed to be the warmest spot on Saturn.[6]"[4]

"A persisting hexagonal wave pattern around the north polar vortex in the atmosphere at about 78°N was first noted in the Voyager images.[7][8]"[4]

The second image at left is Saturn's atmosphere and its rings shown "in a false color composite made from Cassini images taken in near infrared light through filters that sense different amounts of methane gas. Portions of the atmosphere with a large abundance of methane above the clouds are red, indicating clouds that are deep in the atmosphere. Grey indicates high clouds and brown indicates clouds at intermediate altitudes. The rings are bright blue because there is no methane gas between the ring particles and the camera."[9]

"A large, bright and complex convective storm that appeared in Saturn's southern hemisphere in mid-September 2004 was the key in solving a long-standing mystery about the ringed planet."[9]

"The complex feature with arms and secondary extensions just above and to the right of center is called the Dragon Storm. It lies in a region of the southern hemisphere referred to as "storm alley" by imaging scientists because of the high level of storm activity observed there by Cassini in the last year."[9]

"Dragon Storm (dubbed so in September 2004 because of its unusual shape) is a large, bright and complex convective storm in Saturn's southern hemisphere. The Saturnian storm appears to be long-lived and periodically flares up to produce dramatic white plumes which then subside. The storm is a strong source of radio emissions."[10]

X-ray astronomy edit

 
An X-ray astronomy image of Saturn is compared here with the optical image in the visible. Credit: X-ray: NASA/U. Hamburg/J. Ness et al; Optical: NASA/STScI.

The X-ray astronomy image of Saturn is on the left in the composite at right. The Chandra X-ray Observatory "image of Saturn held some surprises for the observers. First, Saturn's 90 megawatts of X-radiation is concentrated near the equator. This is different from a similar gaseous giant planet, Jupiter, where the most intense X-rays are associated with the strong magnetic field near its poles. Saturn's X-ray spectrum, or the distribution of its X-rays according to energy, was found to be similar to that of X-rays from the Sun. This indicates that Saturn's X-radiation is due to the reflection of solar X-rays by Saturn's atmosphere. The intensity of these reflected X-rays was unexpectedly strong. ... The optical image of Saturn is also due to the reflection of light from the Sun - visible wavelength light in this case - but the optical and X-ray images obviously have dramatic differences. The optical image is much brighter, and shows the beautiful ring structures, which were not detected in X-rays. This is because the Sun emits about a million times more power in visible light than in X-rays, and X-rays reflect much less efficiently from Saturn's atmosphere and rings."[11]

Ultraviolet astronomy edit

 
This image of Saturn is taken in ultraviolet light. Credit: NASA and E. Karkoschka (University of Arizona).
This is a movie of Saturn in the ultraviolet from the Hubble Space Telescope. Credit: NASA, ESA, and Jonathan Nichols (University of Leicester).
 
Saturnian aurora whose Lyman alpha false reddish colour in this image is characteristic of ionized hydrogen plasma. Credit: J. Trauger (JPL), NASA.
 
This is an image of Saturn's A Ring, taken by the Cassini Orbiter using an Ultraviolet Imaging Spectrograph. Credit: NASA/JPL/University of Colorado.

"One of a series, this image [at right] of Saturn was taken when the planet's rings were at their maximum tilt of 27 degrees toward Earth. Saturn experiences seasonal tilts away from and toward the sun, much the same way Earth does. This happens over the course of its 29.5-year orbit. Every 30 years, Earth observers can catch their best glimpse of Saturn's south pole and the southern side of the planet's rings. ... NASA's Hubble Space Telescope [captured detailed images of Saturn's Southern Hemisphere and the southern face of its rings."[9]

The movie at right records Saturn "when its rings were edge-on, resulting in a unique movie featuring the nearly symmetrical light show at both of the giant planet's poles. It takes Saturn almost thirty years to orbit the Sun, with the opportunity to image both of its poles occurring only twice during that time. The light shows, called aurorae, are produced when electrically charged particles race along the planet's magnetic field and into the upper atmosphere where they excite atmospheric gases, causing them to glow. Saturn's aurorae resemble the same phenomena that take place at the Earth's poles."[12]

"Powered by the Saturnian equivalent of (filamentary) Birkeland currents, streams of charged particles from the interplanetary medium interact with the planet's magnetic field and funnel down to the poles.[13] Double layers are associated with (filamentary) currents,[14][15] and their electric fields accelerate ions and electrons.[16]"[17]

"Towering more than 1,000 miles above the cloud tops, these Saturnian auroral displays are analogous to Earth's. ... In this false color image, the dramatic red aurora identify emission from atomic hydrogen, while the more concentrated white areas are due to hydrogen molecules."[18]

"The best view of Saturn's rings in the ultraviolet indicates there is more ice toward the outer part of the rings, than in the inner part, hinting at the origins of the rings and their evolution."[19]

"Images taken during the Cassini spacecraft's orbital insertion on June 30 show compositional variation in the A, B and C rings. From the inside out, the "Cassini Division" in faint red at left is followed by the A ring in its entirety. The Cassini Division at left contains thinner, dirtier rings than the turquoise A ring, indicating a more icy composition. The red band roughly three-fourths of the way outward in the A ring is known as the Encke gap."[19]

"The ring system begins from the inside out with the D, C, B and A rings followed by the F, G and E rings. The red in the image indicates sparser ringlets likely made of "dirty," and possibly smaller, particles than in the icier turquoise ringlets."[19]

The image at right "was taken with the Ultraviolet Imaging Spectrograph instrument, which is capable of resolving the rings to show features up to 97 kilometers (60 miles) across, roughly 100 times the resolution of ultraviolet data obtained by the Voyager 2 spacecraft."[19]

Violet astronomy edit

 
This view from Voyager 2 is of Saturn's north polar region through the orange and violet filters. Credit: NASA/JPL.
 
The image shows a subtle northward gradation from gold to azure on Saturn. Credit: NASA/JPL.

"The north polar region of Saturn is pictured in great detail in this Voyager 2 image obtained Aug. 25 from a range of 633,000 kilometers (393,000 miles)."[20]

"Two oval cloud systems some 250 km (150 mi) across are visible at about 72 degrees north latitude. The bright spot in the center of the leftmost cloud is a convective cloud storm about 60 km. (37 mi.)across. The outer ring of material rotates in an anti-cyclonic sense(counterclockwise in the northern hemisphere). A similar cloud structure of comparable dimension appears at 55 degrees north (bottom center of this picture). These northern latitudes contain many bright, small-scale cloud spots--only a few tens of kilometers across--representative of convective cloud systems. Across the top of this image stretch several long, linear, wavelike features that may mark the northernmost east-flowing jet in Saturn's atmosphere."[20]

"In this orange-and-violet-image composite, the smallest features visible are about 16 km. (10 mi.) across."[20]

In the second image at right, "[t]he gas planet's subtle northward gradation from gold to azure is a striking visual effect that scientists don't fully understand. Current thinking says that it may be related to seasonal influences, tied to the cold temperatures in the northern (winter) hemisphere. Despite Cassini's revelations, Saturn remains a world of mystery."[21]

Blue astronomy edit

 
The image shows Saturn's northern hemisphere from the Cassini spacecraft with Mimas in front. Credit: NASA/JPL/Space Science Institute.

In the image at right, "Mimas drifts along in its orbit against the azure backdrop of Saturn's northern latitudes in this true color view from NASA's Cassini spacecraft. The long, dark lines on the atmosphere are shadows cast by the planet's rings."[22]

"Saturn's northern hemisphere is presently relatively cloud-free, and rays of sunlight take a long path through the atmosphere. This results in sunlight being scattered at shorter (bluer) wavelengths, thus giving the northernmost latitudes their bluish appearance at visible wavelengths."[22]

Infrared astronomy edit

 
This is a mosaic of 35 individual exposures taken with infrared radiation. Credit: NASA.
 
This is a false-color composite taken in the infrared of Saturn's south polar region. Credit: NASA/JPL/University of Arizona/University of Leicester.
 
This is an infrared image of Saturn's north pole. Credit: Cassini VIMS Team, University of Arizona, JPL, ESA and NASA.
 
This false-color mosaic shows Saturn's north polar region in infrared from the unlit side. Credit: NASA/JPL/University of Arizona.
 
This image of Saturn is in the infrared. Credit: NASA/E. Karkoschka (University of Arizona).
 
These infrared false-colour images from NASA's Cassini spacecraft chronicle a day in the life of a huge storm that developed from a small spot that appeared 12 weeks earlier in Saturn's northern mid-latitudes. Credit: NASA/JPL-Caltech/SSI.

At right is an infrared astronomy image of Saturn. "This is the sharpest image of Saturn's temperature emissions taken from the ground; it is a mosaic of 35 individual exposures made at the W.M. Keck I Observatory, Mauna Kea, Hawaii on Feb. 4, 2004. The images to create this mosaic were taken with infrared radiation. The black square at 4 o'clock represents missing data."[23]

"In the most precise reading of Saturn's temperatures ever taken from Earth, a new set of infrared images suggests a warm "polar vortex" at Saturn's south pole - the first warm polar cap ever to be discovered in the solar system. The vortex is punctuated by a compact spot that is the warmest place on the planet."[24]

"The puzzle isn't that Saturn's south pole is warm; after all, it has been exposed to 15 years of continuous sunlight, having just reached its summer Solstice late in 2002. But both the distinct boundary of a warm polar vortex some 30 degrees latitude from the southern pole and a very hot "tip" right at the pole were completely unexpected. If the increased southern temperatures are the result of the seasonal variations of sunlight, then temperatures should increase gradually with increasing latitude. But they don't – the tropospheric temperature increases toward the pole abruptly near 70 degrees latitude from 88 to 89 Kelvin (- 301 to -299 degrees Fahrenheit) and then to 91 Kelvin (-296 degrees Fahrenheit) right at the pole. Near 70 degrees latitude, the stratospheric temperature increases even more abruptly from 146 to 150 Kelvin (-197 to -189 degrees Fahrenheit) and then again to 151 Kelvin (-188 degrees Fahrenheit) right at the pole."[24]

The second image at right is "constructed from data collected in the near-infrared wavelengths of light, the auroral emission is shown in green. The data represents emissions from hydrogen ions in of light between 3 and 4 microns in wavelength. In general, scientists designated blue to indicate sunlight reflected at a wavelength of 2 microns, green to indicate sunlight reflected at 3 microns and red to indicate thermal emission at 5 microns. Saturn's rings reflect sunlight at 2 microns, but not at 3 and 5 microns, so they appear deep blue. Saturn's high altitude haze reflects sunlight at both 2 and 3 microns, but not at 5 microns, and so it appears green to blue-green. The heat emission from the interior of Saturn is only seen at 5 microns wavelength in the spectrometer data, and thus appears red. The dark spots and banded features in the image are clouds and small storms that outline the deeper weather systems and circulation patterns of the planet. They are illuminated from underneath by Saturn's thermal emission, and thus appear in silhouette. The composite image was made from 65 individual observations by Cassini's visual and infrared mapping spectrometer on 1 November 2008. The observations were each six minutes long."[25]

The third image at right shows Saturn's northern polar region with "the aurora and underlying atmosphere, seen at two different wavelengths of infrared light as captured by NASA's Cassini spacecraft. Energetic particles, crashing into the upper atmosphere cause the aurora, shown in blue, to glow brightly at 4 microns (six times the wavelength visible to the human eye). The image shows both a bright ring, as seen from Earth, as well as an example of bright auroral emission within the polar cap that had been undetected until the advent of Cassini. This aurora, which defies past predictions of what was expected, has been observed to grow even brighter than is shown here. Silhouetted by the glow (cast here to the color red) of the hot interior of Saturn (clearly seen at a wavelength of 5 microns, or seven times the wavelength visible to the human eye) are the clouds and haze that underlie this auroral region."[26]

Also on the right is a fourth image of Saturn's north polar region in infrared. "This striking false-color mosaic was created from 25 images taken by Cassini's visual and infrared mapping spectrometer over a period of 13 hours, and captures Saturn in nighttime and daytime conditions. The visual and infrared mapping spectrometer acquires data simultaneously at 352 different wavelengths, or spectral channels. Data at wavelengths of 2.3, 3.0 and 5.1 microns were combined in the blue, green and red channels of a standard color image, respectively, to make this false-color mosaic."[27]

"This image was acquired on 24 February 2007, while the spacecraft was 1.58 million km (1 million miles) from the planet and 34.6 degrees above the ring plane. The solar phase angle was 69.5 degrees. In this view, Cassini was looking down on the northern, unlit side of the rings, which are rendered visible by sunlight filtering through from the sunlit, southern face."[27]

"On the night side (right side of image), with no sunlight, Saturn's own thermal radiation lights things up. This light at 5.1 microns wavelength (some seven times the longest wavelength visible to the human eye) is generated deep within Saturn, and works its way upward, eventually escaping into space. Thick clouds deep in the atmosphere block that light. An amazing array of dark streaks, spots and globe-encircling bands is visible instead. Saturn's strong thermal glow at 5.1 microns even allows these deep clouds to be seen on portions of the dayside (left side), especially where overlying hazes are thin and the glint of the sun off of them is minimal. These deep clouds are likely made of ammonium hydrosulfide and cannot be seen in reflected light on the dayside, since the glint of the sun on overlying hazes and ammonia clouds blocks the view of this level."[27]

"A pronounced difference in the brightness between the northern and southern hemispheres is apparent. The northern hemisphere is about twice as bright as the southern hemisphere. This is because high-level, fine particles are about half as prevalent in the northern hemisphere as in the south. These particles block Saturn's glow more strongly, making Saturn look brighter in the north."[27]

"At 2.3 microns (shown in blue), the icy ring particles are highly reflecting, while methane gas in Saturn's atmosphere strongly absorbs sunlight and renders the planet very dark. At 3.0 microns (shown in green), the situation is reversed: water ice in the rings is strongly absorbing, while the planet's sunlit hemisphere is bright. Thus the rings appear blue in this representation, while the sunlit side of Saturn is greenish-yellow in color. Within the rings, the most opaque parts appear dark, while the more translucent regions are brighter. In particular, the opaque, normally-bright B ring appears here as a broad, dark band separating the brighter A (outer) and C (inner) rings."[27]

"At 5.1 microns (shown in red), reflected sunlight is weak and thus light from the planet is dominated by thermal (i.e., heat) radiation that wells up from the planet's deep atmosphere. This thermal emission dominates Saturn's dark side as well as the north polar region (where the hexagon is again visible) and the shadow cast by the A and B rings. Variable amounts of clouds in the planet's upper atmosphere block the thermal radiation, leading to a speckled and banded appearance, which is ever-shifting due to the planet's strong winds."[27]

The fifth infrared image of Saturn is a detailed false color image. "[T]aken in January 1998 by the Hubble Space Telescope [it] shows the ringed planet in reflected infrared light. Different colors [indicate] varying heights and compositions of cloud layers generally thought to consist of ammonia ice crystals. The eye-catching rings cast a shadow on Saturn's upper hemisphere, while the bright stripe seen within the left portion of the shadow is infrared sunlight streaming through the large gap in the rings known as the Cassini Division."[28]

"Two of Saturn's many moons have also put in an appearance (in the full resolution version), Tethys just beyond the planet's disk at the upper right, and Dione at the lower left."[28]

The panoramic images at right "from NASA's Cassini spacecraft chronicle a day in the life of a huge storm that developed from a small spot that appeared 12 weeks earlier in Saturn's northern mid-latitudes."[29]

"This storm is the largest and most intense observed on Saturn by NASA's Voyager or Cassini spacecraft. The storm is still active. As seen in these and other Cassini images, the storm encircles the planet - whose circumference at these latitudes is 300,000 kilometres. From north to south, it covers a distance of about 15,000 kilometres, which is one-third of the way around the Earth. It encompasses an area of 4 billion square kilometres, or eight times the surface area of Earth. This storm is about 500 times the area of the biggest of the southern hemisphere storms ... observed by Cassini."[29]

"The highest clouds in the image are probably around 100 millibars pressure, 100 kilometres above the regular undisturbed clouds. These false colors show clouds at different altitudes. Clouds that appear blue here are the highest and are semitransparent, or optically thin. Those that are yellow and white are optically thick clouds at high altitudes. Those shown green are intermediate clouds. Red and brown colors are clouds at low altitude unobscured by high clouds, and the deep blue color is a thin haze with no clouds below. The base of the clouds, where lightning is generated, is probably in the water cloud layer of Saturn's atmosphere. The storm clouds are likely made out of water ice covered by crystallized ammonia."[29]

"Taken about 11 hours -- or one Saturn day -- apart, the two mosaics in the lower half of this image product consist of 84 images each. The mosaic in the middle was taken earlier than the mosaic at the bottom. Both mosaics were captured on Feb. 26, 2011, and each of the two batches of images was taken over about 4.5 hours."[29]

"Two enlargements from the earlier, middle mosaic are shown at the top of this product. The white lines below the middle mosaic identify those parts of the mosaic that were enlarged for these close-up views. The enlargement on the top left shows the head of the storm, and that on the top right shows the turbulent middle of the storm. Cassini observations have shown the head of the storm drifting west at a rate of about 2.8 degrees of longitude each Earth day (28 meters per second, or 63 miles per hour). The central latitude of the storm is the site of a westward jet, which means that the clouds to the north and south are drifting westward more slowly or even drifting eastward. In contrast, clouds at Saturn's equator drift eastward at speeds up to 450 meters per second (1,000 miles per hour). "[29]

"Both of the long mosaics cover an area ranging from about 30 degrees north latitude to 51 degrees north latitude. The views stretch from about 138 degrees west longitude on the left to 347 degrees west longitude on the right, passing through 360/0 degrees west longitude near the far right of the mosaics."[29]

"The images were taken with the Cassini spacecraft narrow-angle camera using a combination of spectral filters sensitive to wavelengths of near-infrared light. The images filtered at 889 nanometers are projected as blue. The images filtered at 727 nanometers are projected as green, and images filtered at 750 nanometers are projected as red."[29]

"The views were acquired at a distance of approximately 2.4 million kilometres from Saturn and at a sun-Saturn-spacecraft angle (phase angle) of 62 degrees. Both the top and bottom images are simple cylindrical map projections, defined such that a square pixel subtends equal intervals of latitude and longitude. At higher latitudes, the pixel size in the north-south direction remains the same, but the pixel size in the east-west direction becomes smaller. The pixel size is set at the equator, where the distances along the sides are equal. The images of the long mosaics have a pixel size of 53 kilometres at the equator, and the two close-up views have a pixel size of 9 kilometres per pixel at the equator."[29]

Submillimeter astronomy edit

"[T]he PH3 1-0 rotational line (266.9 GHz) line [has been detected] in [the atmosphere of] Saturn"[30].

Radio astronomy edit

 
In this simulated image of Saturn's rings, color is used to present information about ring particle sizes in different regions based on the measured attenuations of three radio signals. Credit: NASA / Jet Propulsion Lab.

"Three simultaneous radio signals at wavelengths of 0.94, 3.6, and 13 centimeters (Ka-, X-, and S-bands) were sent from Cassini through the rings to Earth. The observed change of each signal as Cassini moved behind the rings provided a profile of the distribution of ring material and an optical depth profile."[31]

"This simulated image was constructed from the measured optical depth profiles of the Cassini Division and ring A. It depicts the observed structure at about 10 kilometers (6 miles) in resolution. The image shows the same ring A region depicted in a similar image (Multiple Eyes of Cassini), using a different color scheme to enhance the view of a remarkable array of over 40 wavy features called 'density waves' uncovered in the May 3 radio occultation throughout ring A."[31]

"Color is used to represent information about ring particle sizes based on the measured effects of the three radio signals. Shades of red [purple] indicate regions where there is a lack of particles less than 5 centimeters (about 2 inches) in diameter. Green and blue shades indicate regions where there are particles of sizes smaller than 5 centimeters (2 inches) and 1 centimeter (less than one third of an inch), respectively."[31]

"Note the gradual increase in shades of green towards the outer edge of ring A. It indicates gradual increase in the abundance of 5-centimeter (2-inch) and smaller particles. Note also the blue shades in the vicinity of the Keeler gap (the narrow dark band near the edge of ring A). They indicate increased abundance of even smaller particles of diameter less than a centimeter. Frequent collisions between large ring particles in this dynamically active region likely fragment the larger particles into more numerous smaller ones."[31]

Atmospheric astronomy edit

 
This is a Cassini image in natural color of the gaseous object Saturn. Credit: NASA/JPL/Space Science Institute.

"The planet exhibits a pale yellow hue due to ammonia crystals in its upper atmosphere. ... [Its] exterior is predominantly composed of gas and it lacks a definite surface ... The planet primarily consists of hydrogen ... The outer atmosphere of Saturn contains 96.3% molecular hydrogen and 3.25% helium.[32] ... The proportion of helium is significantly deficient compared to the abundance of this element in the Sun.[33] ... Trace amounts of ammonia, acetylene, ethane, propane, phosphine and methane have been detected in Saturn's atmosphere.[34][35][36]"[1]

Stellar science edit

"Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. [It is n]amed after the Roman god Saturn ... Saturn is a gas giant with an average radius about nine times that of Earth.[37][38] ... Saturn has a ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust. Sixty-two[39] known moons orbit the planet; fifty-three are officially named. This does not include the hundreds of "moonlets" within the rings."[40]

Classical planets edit

 
The planet Saturn is seen in approximate natural color by the Hubble Space Telescope. Credit: Hubble Heritage Team (AURA/STScI/NASA/ESA).

"Saturday is the day of Saturn, and the color of Saturn, according to astronomers, is said to be black"[41].

“Saturn has been known since prehistoric times.[42][4].

Apparently 5102 b2k (before the year 2000.0), -3102 or 3102 BC, is the historical year assigned to a Hindu table of planets that does include the classical planet Saturn.[43] "Babylonian astronomy, too, had a four-planet system. In ancient prayers the planets Saturn, Jupiter, Mars, and Mercury are invoked; ... and one speaks of "the four-planet system of the ancient astronomers of Babylonia."[44]"[45]

Babylonian astronomers systematically observed and recorded the movements of Saturn.[46][4].

“Ancient Chinese and Japanese culture designated the planet Saturn as the earth star[4].

“In ancient Hebrew, Saturn is called 'Shabbathai'.[47] Its angel is Cassiel. Its intelligence or beneficial spirit is Agiel (layga) and its spirit (darker aspect) is Zazel (lzaz).”[4].

“In Ottoman Turkish, Urdu and Malay, its name is 'Zuhal'”[4].

Anu edit

Anu may be an early Sumerian, Akkadian, and Babylonian name for Saturn.

"An, the oldest and highest of the Sumero-Babylonian gods, whose primordial age was "the year of abundance," signified Saturn, according to Jensen.6"[48]

Baal-hamon edit

"The potential cruelty of Saturn was enhanced by his identification with Cronus, known for devouring his own children. He was thus equated with the Carthaginian god Ba'al Hammon, to whom children were supposedly sacrificed. Saturn was also among the gods the Romans equated with Yahweh, whose Sabbath (on Saturday) he shared as his holy day."[49]

"Modern scholars identify [Baal-hamon] variously with the Northwest Semitic god El or with Dagon.[50]"[51]

"Ancient Greek writers identified him with the Titan Cronus. In ancient Rome, he was identified with Saturn"[51].

Cronus edit

“The Greeks had made the outermost planet sacred to Cronus,[52] and the Romans followed suit.”[4].

El edit

"In the Canaanite religion, or Levantine religion as a whole, Ēl or Il was the supreme god, the father of humankind and all creatures and the husband of the goddess Asherah as recorded in the clay tablets of Ugarit ... The noun ʾēl was found at the top of a list of gods as the "Ancient of gods" or the "Father of all gods", in the ruins of the royal archive of the Ebla civilization, in the archaeological site of Tell Mardikh in Syria dated to 2300 BC."[53]

"Ēl (rendered Elus or called by his standard Greek counterpart Cronus) is not the creator god or first god. Ēl is rather the son of Sky and Earth."[53]

"Joseph Fontenrose first demonstrated that, whatever their deep origins, at Ugarit Dagon was identified with El,[54]"[55]

Osiris edit

 
The gods Osiris, Anubis, and Horus are shown from a tomb painting. Credit: A. Parrot.
 
This is a detail of a frieze on a wall of tomb QV66, the burial place of Nefertari (c. 1295-1255 B.C.), royal wife of Ramesses the Great, featuring the Egyptian god Osiris. Credit: Mrgoodgame.

"Osiris is the mythological father of the god Horus, whose conception is described in the Osiris myth, a central myth in ancient Egyptian belief. The myth described Osiris as having been killed by his brother Seth, who wanted Osiris' throne. Isis joined the fragmented pieces of Osiris, but the only body part missing was the phallus. Isis fashioned a golden phallus, and briefly brought Osiris back to life by use of a spell that she learned from her father. This spell gave her time to become pregnant by Osiris before he again died. Isis later gave birth to Horus. As such, since Horus was born after Osiris' resurrection, Horus became thought of as a representation of new beginnings and the vanquisher of the evil Set."[56]

"The Phoenician El - Saturn - has four eyes, as does the Orphic Kronos (Saturn)."[48]

"The Chinese Yellow Emperor Huang-ti--identified as Saturn--is also four-eyed.74"[48]

"Osiris, as the Ram of Mendes, is the god of "four faces on one neck."62"[48]

Have observers recorded images of sky entities in the green?

Saturnus edit

“In ancient Roman mythology, the god Saturnus, from which the planet takes its name, was the god of agriculture.[57] The Romans considered Saturnus the equivalent of the Greek god Cronus.[57][4].

“The Latins considered Saturn the predecessor of Jupiter. Saturn reigned in Latium during a mythical Golden Age reenacted every year at the festival of Saturnalia. Saturn also retained primacy in matters of agriculture and money. Unlike the Greek tradition of Cronus and Zeus, the usurpation of Saturn as king of the gods by Jupiter was not viewed by the Latins as violent or hostile; Saturn continued to be revered in his temple at the foot of the Capitol Hill, which maintained the alternative name Saturnius into the time of Varro.[58][59]

Wanderers edit

"There is one God, greatest among gods and men, neither in shape nor in thought like unto mortals ... He abides ever in the same place motionless, and it befits him not to wander hither and thither."[60]

"Saturn, the old man who lives at the north pole, and brings with him to the children of men a sprig of evergreen (the Christmas tree), is familiar to the little folks under the name Santa Claus, for he brings each winter the gift of a new year."[61]

"The religions of all ancient nations ... associate the abode of the supreme God with the North Pole, the centre of heaven; or with the celestial space immediately surrounding it."[62]

"Lenormant, speaking of Rome and Olympia, remarks, "It is impossible not to note that the Capitoline was first of all the Mount of Saturn, and that the Roman archaeologists established a complete affinity between the Capitoline and Mount Cronios in Olympia, from the standpoint of their traditions and religious origin (Dionysius Halicarn., i., 34). This Mount Cronios is, as it were, the Omphalos of the sacred city of Elis, the primitive centre of its worship. It sometimes receives the name Olympos."1 Here is not only symbolism in general, but also a symbolism pointing to the Arctic Eden, already shown to be the primeval mount of Kronos, the Omphalos of the whole earth.2"[62]

"As an offshoot of these Hellenistic speculations we should place Tacitus, Histories V,2: "Iudaeos Creta insula profugos novissima Libyae insedisse memorant, qua tempestate Saturnus vi Jovis pulsus cesserit regnis" (quoted from Loeb Classical Library)."[63] i.e., "Jews were fugitives from the island of Crete and settled in Libya recorded the time when Saturn was driven from his throne by force of Jupiter".

"The motif of Saturn handing over power to Jupiter derives, of course, from Hesiod's account of the succession of the gods in his Theogony, and his story of the five successive ages of men -- the first, or golden, age being under the reign of Kronos (Saturn) and the following ages being under the reign of Zeus (Jupiter) -- in his Works and Days (110ff.). These stories were often retold. Ovid, for example, combines in his Metamorphoses the stories in the Theogony and Works and Days, telling us how, "when Saturn was consigned to the darkness of Tartarus, and the world passed under the rule of Jove, the age of silver replaced that of gold."8"[64]

See also edit

References edit

  1. 1.0 1.1 "Saturn". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). February 20, 2013. http://en.wikipedia.org/wiki/Saturn. Retrieved 2013-02-20. 
  2. Pérez-Hoyos, S.; Sánchez-Laveg, A.; French, R. G.; J. F., Rojas (2005). "Saturn's cloud structure and temporal evolution from ten years of Hubble Space Telescope images (1994–2003)". Icarus 176 (1): 155–174. doi:10.1016/j.icarus.2005.01.014. 
  3. Patrick Moore, ed., 1993 Yearbook of Astronomy, (London: W.W. Norton & Company, 1992), Mark Kidger, "The 1990 Great White Spot of Saturn", pp. 176–215.
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 "Saturn". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). May 8, 2012. http://en.wikipedia.org/wiki/Saturn. Retrieved 2012-05-11. 
  5. Hamilton, Calvin J. (1997). "Voyager Saturn Science Summary". Solarviews. Archived from the original on 2011-10-05. Retrieved 2007-07-05.
  6. 6.0 6.1 "Warm Polar Vortex on Saturn". Merrillville Community Planetarium. 2007. Archived from the original on 2011-10-05. Retrieved 2007-07-25.
  7. Godfrey, D. A. (1988). "A hexagonal feature around Saturn's North Pole". Icarus 76 (2): 335. doi:10.1016/0019-1035(88)90075-9. 
  8. Sanchez-Lavega, A.; Lecacheux, J.; Colas, F.; Laques, P. (1993). "Ground-based observations of Saturn's north polar SPOT and hexagon". Science 260 (5106): 329. doi:10.1126/science.260.5106.329. PMID 17838249. 
  9. 9.0 9.1 9.2 9.3 Samantha Harvey; Autumn Burdick (September 15, 2004). "The Dragon Storm". NASA/JPL/Space Science Institute. Retrieved 2013-04-27. Cite error: Invalid <ref> tag; name "Harvey" defined multiple times with different content
  10. "Dragon Storm (astronomy)". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). February 22, 2013. http://en.wikipedia.org/wiki/Dragon_Storm_(astronomy). Retrieved 2013-04-27. 
  11. Samantha Harvey (August 19, 2008). "X-Ray Saturn". NASA. Retrieved 2012-07-21.
  12. Jonathan Nichols (February 11, 2010). "Double light show in a single shot: Hubble images both of Saturn's aurorae". NASA and Hubble Space Telescope. Retrieved 2012-07-21.
  13. Isbell, J.; Dessler, A. J.; Waite, J. H. "Magnetospheric energization by interaction between planetary spin and the solar wind" (1984) Journal of Geophysical Research, Volume 89, Issue A12, pp. 10715–10722
  14. Theisen, William L. "Langmuir Bursts and Filamentary Double Layers in Plasmas." (1994) Ph.D Thesis U. of Iowa, 1994
  15. Deverapalli, C. M.; Singh, N.; Khazanov, I. "Filamentary Structures in U-Shaped Double Layers" (2005) American Geophysical Union, Fall Meeting 2005, abstract #SM41C-1202
  16. Borovsky, Joseph E. "Double layers do accelerate particles in the auroral zone" (1992) Physical Review Letters (ISSN 0031-9007), vol. 69, no. 7, Aug. 17, 1992, pp. 1054–1056
  17. "Double layer (plasma)". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). October 16, 2012. http://en.wikipedia.org/wiki/Double_layer_(plasma). Retrieved 2012-11-16. 
  18. Robert Nemiroff; Jerry Bonnell (December 23, 2001). "Saturn Aurora". Greenbelt, Maryland, USA: JPL, NASA GSFC. Retrieved 2012-11-16.
  19. 19.0 19.1 19.2 19.3 University of Colorado (July 9, 2004). "PIA05075: Saturn's A Ring From the Inside Out". Pasadena, California USA: NASA/JPL. Retrieved 2013-03-27.
  20. 20.0 20.1 20.2 Ciclops (August 25, 1981). "Saturn - north polar region (NASA Voyager Saturn Encounter Images)". Pasadena, California USA: NASA/JPL. Retrieved 2013-03-27.
  21. Enrico Piazza (December 22, 2005). "The Face of Beauty". Pasadena, California USA: NASA/JPL. Retrieved 2013-03-27.
  22. 22.0 22.1 Jim Wilson (March 23, 2008). "Saturn's Blues". Pasadena, California USA: NASA/JPL. Retrieved 2013-03-27.
  23. "File:Saturn polar vortex.jpg". Wikimedia Commons (San Francisco, California: Wikimedia Foundation, Inc). October 3, 2009. http://commons.wikimedia.org/wiki/File:Saturn_polar_vortex.jpg. Retrieved 2012-07-21. 
  24. 24.0 24.1 Carolina Martinez; Laura K. Kraft (February 3, 2005). "Saturn's Bull's-Eye Marks Its Hot Spot". NASA. Retrieved 2012-07-21.
  25. Samantha Harvey (March 29, 2011). "Glowing Southern Lights". NASA. Retrieved 2012-07-21.
  26. Sue Lavoie (November 12, 2008). "PIA11396: Saturn's Polar Aurora". Tucson, Arizona: JPL/NASA/University of Arizona. Retrieved 2012-07-21.
  27. 27.0 27.1 27.2 27.3 27.4 27.5 Samantha Harvey (September 20, 2011). "Neon Saturn". NASA. Retrieved 2012-07-21.
  28. 28.0 28.1 Yvette Smith (March 23, 2008). "The Colors of Saturn". NASA. Retrieved 2012-07-21.
  29. 29.0 29.1 29.2 29.3 29.4 29.5 29.6 29.7 Andy Ingersoll; Ulyana Dyudina; Shawn Ewald; Carolyn Porco; Daiana DiNino; Joe Mason (July 6, 2011). "A Day in the Life". Cassini Imaging Central Laboratory for Operations. Retrieved 2012-11-26.
  30. Eric Wolfgang Weisstein (January 1996). Millimeter/submillimeter Fourier Transform Spectroscopy of Jovian Planet Atmospheres. California Institute of Technology. Bibcode: 1996PhDT.........5W. 
  31. 31.0 31.1 31.2 31.3 Enrico Piazza (May 23, 2005). "Waves and Small Particles in Ring A". Pasadena, California USA: NASA/JPL. Retrieved 2013-03-27.
  32. Saturn. Universe Guide. Retrieved 29 March 2009.
  33. Guillot, Tristan et al. (2009). "Saturn's Exploration Beyond Cassini-Huygens". In Dougherty, Michele K.; Esposito, Larry W.; Krimigis, Stamatios M.. Saturn from Cassini-Huygens. Springer Science+Business Media B.V.. p. 745. doi:10.1007/978-1-4020-9217-6_23. ISBN 978-1-4020-9216-9. Bibcode: 2009sfch.book..745G. 
  34. Courtin, R. et al. (1967). "The Composition of Saturn's Atmosphere at Temperate Northern Latitudes from Voyager IRIS spectra". Bulletin of the American Astronomical Society 15: 831. 
  35. Cain, Fraser (January 22, 2009). "Atmosphere of Saturn". Universe Today. Archived from the original on 2011-10-05. Retrieved 2011-07-20.
  36. Guerlet, S.; Fouchet, T.; Bézard, B. (November 2008), "Ethane, acetylene and propane distribution in Saturn's stratosphere from Cassini/CIRS limb observations", in Charbonnel, C.; Combes, F.; Samadi, R. (eds.), SF2A-2008: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics, p. 405, Bibcode:2008sf2a.conf..405G
  37. Brainerd, Jerome James (November 24, 2004). "Characteristics of Saturn". The Astrophysics Spectator. Archived from the original on 2011-10-05. Retrieved 2010-07-05.
  38. "General Information About Saturn". Scienceray. July 28, 2011. Archived from the original on 2011-10-05. Retrieved 2011-08-17.
  39. Piazza, Enrico. "Saturn's Moons". Cassini, Equinox Mission. JPL NASA. Archived from the original on 2011-10-05. Retrieved 2010-06-22.
  40. "Saturn". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). June 16, 2012. http://en.wikipedia.org/wiki/Saturn. Retrieved 2012-07-08. 
  41. Glenn D. Lowry (1987). "Humayun's Tomb: Form, Function, and Meaning in Early Mughal Architecture". Muqarnas 4: 133-48. doi:10.2307/1523100. http://www.jstor.org/stable/10.2307/1523100. Retrieved 2012-04-24. 
  42. "Saturn > Observing Saturn". National Maritime Museum. Archived from the original on 2007-04-22. Retrieved 2007-07-06.
  43. Jean Baptiste Joseph Delambre (1817). Histoire de l'astronomie ancienne. Paris: Courcier. pp. 639. http://books.google.com/books?id=2lVUjJSxjhQC&pg=PR3&source=gbs_selected_pages&cad=3#v=onepage&f=false. Retrieved 2012-01-13. 
  44. Ernst Friedrich Weidner (1915). Handbuch der babylonischen Astronomie, Volume 1. J. C. Hinrichs. pp. 146. http://books.google.com/books?id=K6NDAAAAYAAJ&hl=en. Retrieved 2012-03-30. 
  45. Immanuel Velikovsky (January 1965). Worlds in Collision. New York: Dell Publishing Co., Inc.. pp. 401. http://books.google.com/books?id=FJst27kSVBgC&pg=PA13&dq=%22Worlds+in+Collision%22+1965&hl=en. Retrieved 2012-01-13. 
  46. A. Sachs (May 2, 1974). "Babylonian Observational Astronomy". Philosophical Transactions of the Royal Society of London (Royal Society of London) 276 (1257): 43–50 [45 & 48–9]. doi:10.1098/rsta.1974.0008. 
  47. Cessna, Abby (November 15, 2009). "When Was Saturn Discovered?". Universe Today. Archived from the original on 2011-10-05. Retrieved July 21, 2011.
  48. 48.0 48.1 48.2 48.3 David N. Talbott (1980). The Saturn Myth. Garden City, New York, USA: Knopf Doubleday & Company, Inc.. pp. 419. ISBN 0-385-11376-5. http://books.google.com/books?id=tNVlQgAACAAJ&hl=en. Retrieved 2013-01-03. 
  49. "Saturn (mythology)". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). October 14, 2012. http://en.wikipedia.org/wiki/Saturn_(mythology). Retrieved 2012-10-15. 
  50. "Carthaginian Religion by Roy Decker". About.com. Retrieved 2010-07-07.
  51. 51.0 51.1 "Baal-hamon". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). May 11, 2012. http://en.wikipedia.org/wiki/Baal-hamon. Retrieved 2012-10-15. 
  52. James Evans (1998). The History and Practice of Ancient Astronomy. Oxford University Press. pp. 296–7. ISBN 978-0-19-509539-5. https://www.amazon.com/History-Practice-Ancient-Astronomy/dp/0195095391. 
  53. 53.0 53.1 "El (deity)". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). October 11, 2012. http://en.wikipedia.org/wiki/El_(god). Retrieved 2012-10-15. 
  54. Joseph Fontenrose, "Dagon and El" Oriens 10.2 (December 1957), pp. 277-279.
  55. "Dagon". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). September 30, 2012. http://en.wikipedia.org/wiki/Dagon. Retrieved 2012-10-15. 
  56. "Osiris". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). January 22, 2013. http://en.wikipedia.org/wiki/Osiris. Retrieved 2013-01-22. 
  57. 57.0 57.1 "Starry Night Times". Imaginova Corp. 2006. Archived from the original on 2011-08-21. Retrieved 2007-07-05.
  58. Varro V 42; Vergil Aeneis VIII 357-8; Dionysius Hal. I 34; Solinus I 12; Festus p. 322 L; Tertullian Apologeticum 10; Macrobius I 7, 27 and I 10, 4 citing a certain Mallius. See also Macrobius I 7, 3: the annalistic tradition attributed its foundation to king Tullus Hostilius. Studies by E. Gjerstad in Mélanges Albert Grenier Bruxelles 1962 p. 757-762; Filippo Coarelli in La Parola del Passato 174 1977 p. 215 f.
  59. "Jupiter (mythology)". Wikipedia (San Francisco, California: Wikimedia Foundation, Inc). May 11, 2012. http://en.wikipedia.org/wiki/Jupiter_(mythology). Retrieved 2012-05-11. 
  60. Joseph Campbell (June 26, 2008). The Masks of God: Occidental Mythology. Paw Prints. pp. 564. ISBN 1439508925. http://books.google.com/books?id=fqGdPwAACAAJ&hl=en. Retrieved 2013-01-06. 
  61. Manly Palmer Hall (1928). Secret Teachings of All Ages. San Francisco: Hall Publishing Company. pp. 648. http://books.google.com/books?id=FDSab8rWZScC&pg=PR1&source=gbs_selected_pages&cad=3. Retrieved 2013-01-06. 
  62. 62.0 62.1 William Fairfield Warren (1885). Paradise Found The Cradle of the Human Races at the North Pole. Boston: Houghton, Mifflin and Company. http://books.google.com/books?id=Nj4RTbq_xyYC&printsec=frontcover&hl=en#v=onepage&f=false. Retrieved 2013-01-06. 
  63. John Strange (1980). Caphtor/Keftiu: A New Investigation. Brill Archive. pp. 227. ISBN 9004062564. http://books.google.com/books?id=c9QUAAAAIAAJ&pg=PA123&hl=en#v=onepage&f=false. Retrieved 2013-01-11. 
  64. David Ulansey (1989). The Origins of the Mithraic Mysteries: Cosmology and Salvation in the Ancient World. Oxford, England: Oxford University Press. ISBN 0-19-505402-4. http://books.google.com/books?id=25_SOWldSUUC&pg=PA100&lpg=PA100&source=bl&ots=N3diINc8CU&sig=uJ5kxBfQDieM0pVdttM_ZRvs3tw&hl=en#v=onepage&f=false. Retrieved 2013-01-13. 

Further reading edit

External links edit

{{Astronomy resources}} {{Principles of radiation astronomy}}