quarta-feira, 11 de março de 2015

Lua e Saturno, na madrugada sonolenta e concluidora do verão



Olá!

Na madrugada de amanhã, dia 12 de março, 
a Lua estará saudando Saturno
- que vem fazendo parte das estrelas que compõem as Garras (ou Cabeça)
da constelação Scorius.

Belo espetáculo a ser observado
e a ser fotogrado, não é verdade?

Com um abraço estrelado,
Janine Milward


Programa Stellarium

Programa Stellarium

Programa Stellarium

Programa Stellarium




SATURNO !!!

Saturno é o sexto planeta a partir do Sol e o segundo maior do Sistema Solar atrás de Júpiter
O interior de Saturno é provavelmente formado por um núcleo de ferroníquel e rocha (composto de silício e oxigênio), cercado por uma profunda camada dehidrogênio metálico, uma camada intermediária de hidrogênio e hélio líquido e uma exterior gasosa.12 O planeta possui um tom amarelo claro por causa dos cristais de amônia em sua atmosfera superior. Acredita-se que correntes elétricas dentro da camada de hidrogênio metálico criam seu campo magnéticoplanetário, que é mais fraco que o da Terra porém com um momento magnético 580 vezes maior por causa de seu tamanho. A força do campo magnético de Saturno é por volta de um vigésimo do de Júpiter.13 Sua atmosfera exterior é suave e com poucos contrastes, apesar características de longa duração podendo aparecer. O vento pode chegar a uma velocidade de 1 800 km/h, mais rápidos que os de Júpiter, porém menores que os de Netuno.14
Saturno possui um proeminente sistema de anéis que consiste em nove anéis principais contínuos e três arcos descontínuos, compostos principalmente de partículas de gelo com uma quantidade menor de detritos rochosos e poeira. Saturno tem 62 satélites conhecidos,15 dos quais 53 possuem um nome oficial. Isso não inclui centenas de "pequenos satélites" compreendendo os anéis. Titã, seu maior satélite e o segundo maior do Sistema Solar, é maior que o planeta Mercúrioe o único satélite que possui uma atmosfera substancial.16
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Órbita

Saturno gira em torno do Sol em uma distância media de 1,418 bilhões de quilômetros em uma órbita de excentricidade 0,056, com um afélio a 1,500 bilhões de quilômetros e o periélio a 1,240 bilhões de quilômetros. Saturno esteve no periélio em 1974. O período da translação em torno do sol completa a cada 29 anos e 167 dias, visto que seuPeríodo sinódico se realiza de 378 dias, de modo que , a cada ano a oposição ocorre com quase duas semanas de atraso em relação ao ano anterior. O período de rotação em seu eixo é curto, de 10 horas, 14 minutos, com algumas variações entre o equador e os pólos.
Os elementos orbitais de Saturno são alterados em uma escala de 900 anos por uma ressonância orbital do tipo de 5:2 com o planeta Júpiter, batizado pelos astrônomos franceses do século XVIII como a grand inégalité ("grande desigualdade"), Júpiter completa 5 retornos para cada 2 de Saturno. Os planetas não estão em uma ressonância perfeita, mas são suficientemente próximo de modo que os distúrbios de suas órbitas sejam apreciáveis.
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LEIA MAIS EM





  • Title Golden rings
  • Released 15/08/2004 12:00 am
  • Copyright NASA/JPL/Space Science Institute
  • DescriptionSaturn's rings appear golden as the planet's shadow drapes across nearly the whole span of the rings. In the upper left corner is Saturn's moon Mimas. Mimas is 398 kilometres wide.

    The shadow of Saturn's southern hemisphere stretches almost entirely across the rings. The outermost, narrow F ring is visible here.
    This colour image was taken on 15 August 2004, with the NASA/ESA/ASI Cassini-Huygens spacecraft narrow-angle camera, using the red, green and blue filters.
    The image was taken 8.8 million kilometres from Saturn. Contrast has been enhanced to aid visibility.
  • Id 215528




Saturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first to gaze at Saturn through a telescope. To his surprise, he saw a pair of objects on either side of the planet. He sketched them as separate spheres, thinking that Saturn was triple-bodied. Continuing his observations over the next few years, Galileo drew the lateral bodies as arms or handles attached to Saturn. In 1659, Dutch astronomer Christiaan Huygens, using a more powerful telescope than Galileo's, proposed that Saturn was surrounded by a thin, flat ring. In 1675, Italian-born astronomer Jean-Dominique Cassini discovered a "division" between what are now called the A and B rings. It is now known that the gravitational influence of Saturn's moon Mimas is responsible for the Cassini Division, which is 4,800 kilometers (3,000 miles) wide.
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http://solarsystem.nasa.gov/planets/profile.cfm?Object=Saturn&Display=OverviewLong


Minha (Janine) tradução simples e direta:

Saturno era o mais distante dos cinco planetas conhecidos pelos povos antigos.  Em 1610, o astrônomo italiano Galileo Galilei foi o primeiro a observar Saturno através um telescópio.  Para sua surpresa, ele viu um par de objetos em ambos os lados do planeta.  Ele desenhou-os como se fossem esferas separadas, pensando que Saturno era composto de três corpos.  Ao dar continuidade às suas observações através os anos seguintes, Galileo desenhou os corpos lateris como se fossem braços ou alças anexadas a Saturno. Em 1659, o astrônomo holandês Christiann Huygens, usando um telescópio mais potente do que o de Galileo, propôs que Saturno era rodeado por um anel fino e achatado.  Em 1675, Jean-Dominique Cassini, um astrônomo nascido na Itália, descobriu uma "divisão" entre aquilo que ele nomeou como anéis A e B.  Hoje em dia sabe-se que a influência gravitacional de uma das Luas de Saturno, Mimas, é presonsável pela Divisão de Cassini, a qual possui 4.800 quilômetros (3 mil milhas) de extensão.

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Significant Dates
  • 1610: Galileo Galilei reports seeing odd appendages on either side of Saturn; he did not realize he was viewing Saturn's rings.
  • 1979: Pioneer 11 is the first spacecraft to reach Saturn, flying within 22,000 kilometers (13,700 miles) of the cloud tops.
  • 1981: Using Saturn's powerful gravity as an interplanetary slingshot, Voyager 2 is placed on a path toward Uranus, then Neptune, then out of the solar system.
  • 1994: The Hubble Space Telescope finds evidence of surface features beneath the hazy atmosphere of Titan.
  • 2004: After a seven-year journey, Cassini-Huygens becomes the first spacecraft to orbit Saturn.
  • 2005: The Huygens probe successfully lands on Titan, returning images of the complex surface.
  • 2005-2008: The Cassini spacecraft continues to return high-resolution images of the Saturn system. Mission discoveries include evidence for liquid hydrocarbon lakes of methane and ethane on Titan, a new radiation belt around Saturn, new rings and moons, and icy jets and geysers at the south polar region of the moon Enceladus.
  • 2008-2010: Cassini's mission is extended for two years and designated the Cassini Equinox Mission.
  • 2010-2017: Cassini's mission is extended for seven years and designated the Cassini Solstice Mission.








  • Title Saturn’s rainbow rings
  • Released 05/05/2014 11:55 am
  • Copyright NASA/JPL/University of Colorado
  • DescriptionThis colourful cosmic rainbow portrays a section of Saturn’s beautiful rings, four centuries after they were discovered by Galileo Galilei.
    Saturn’s rings were first observed in 1610. Despite using his newly created telescope, Galileo was confounded by what he saw: he referred to the peculiar shapes surrounding the planet as “Saturn’s children”. Only later did Christiaan Huygens propose that the mysterious shapes were actually rings orbiting the planet. These were named in the order in which they were discovered, using the first seven letters of the alphabet: the D-ring is closest to the planet, followed by C, B, A, F, G and E.
    The data for this image, which shows the portion of the C-ring closest to Saturn on the left, with the B-ring beginning just right of centre, were acquired by Cassini’s Ultraviolet Imaging Spectrograph, or UVIS, as the spacecraft entered into orbit around Saturn on 30 June 2004.
    UVIS, as its name suggests, carries out observations in ultraviolet wavelengths. During the Saturn orbit insertion manoeuvre, when Cassini flew closest to the rings, UVIS could resolve features up to 97 km across. The region shown in this image spans about 10 000 km.
    The variation in the colour of the rings arises from the differences in their composition. Turquoise-hued rings contain particles of nearly pure water ice, whereas reddish rings contain ice particles with more contaminants.
    Saturn’s prominent and complex ensemble of rings is the best studied in the Solar System, but it is still not known how the rings formed. One suggestion is that they formed at the same time as the planet and that they are as old as the Solar System. Another idea is that they formed when icy material was pulled from another body into Saturn’s gravitational field, in which case the rings could be younger than the planet.
    One thing is sure: as Cassini searches for answers it is providing amazing images of these rainbow rings.
    The Cassini–Huygens mission is a cooperative project of NASA, ESA and Italy’s ASI space agency.

    This image was first published at the NASA Cassini website, in 2004.
  • Id 310417




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Anéis de Saturno

Os anéis de Saturno são constituídos essencialmente por uma mistura de gelo, poeiras e material rochoso. Se estendem a cerca de 280 mil quilômetros de diâmetro, não ultrapassam 1,5 km de espessura. A origem dos anéis é desconhecida. Originalmente pensou-se que teriam tido origem na formação dos planetas há cerca de 4 bilhões de anos, mas estudos recentes apontam para que sejam mais novos, tendo apenas algumas centenas de milhões de anos. Alguns cientistas acreditam que os anéis se formaram a partir de uma colisão que ocorreu perto do planeta ou com o planeta. Pensa-se que os anéis de Saturno desaparecerão um dia, cerca de 100 milhões de anos, pois vão sendo lentamente puxados para o planeta. Os anéis podem mudar de cor.
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This highly enhanced color view was assembled from clear, orange and ultraviolet frames obtained 17 August 1981 from a distance of 8.9 million km (5.5 million miles).



The rings of Saturn have puzzled astronomers since Galileo Galilei discovered them with his telescope in 1610. Detailed study by the Voyager 1 and Voyager 2spacecraft in the 1980s only increased the mystery.

There are billions of ring particles in the entire ring system. The ring particle sizes range from tiny, dust-sized icy grains to a few particles as large as mountains. Two tiny moons orbit in gaps (Encke and Keeler gaps) in the rings and keep the gaps open. Other particles (10s to 100s of meters) are too tiny to see, but create propeller-shaped objects in the rings that let us know they are there. The rings are believed to be pieces of cometsasteroids or shattered moons that broke up before they reached the planet. Each ring orbits at a different speed around the planet. Information from NASA's Cassini mission will help reveal how they formed, how they maintain their orbit and, above all, why they are there in the first place.

While the other three gas planets in the solar system -- JupiterUranus and Neptune-- have rings orbiting around them, Saturn's are by far the largest and most spectacular. With a thickness of about one kilometer (3,200 feet) or less, they span up to 282,000 km (175,000 miles), about three quarters of the distance between theEarth and its Moon.



Minha (Janine) tradução simples e direta:

Os anéis de Saturno vêm surpreendendo os astrônomos desde Galileo Galilei em sua descoberta através seu telescópio em 1610.  Estudos detalhados realizados pelas naves  Voyager 1 e Voyager 2, na década dos anos 1980, somente ampliou o mistério.

Existem bilhões de partículas de anéias em todo o sistema anelar.  Os tamanhos das partículas de anéis variam de pequeníssimos grãos de gelo e poeira a algumas partículas tão grandes quanto montanhas.  Duas pequenas luas orbitam nos vazios (Fendas Encke e Keeler) nos anéis e fazem com que estas fendas permaneçam abertas.  Outras partículas (10s a 100s metros) são tão pequenas que mal podem ser vistas porém criam objetos em formato de propulsão própria nos anéis de maneira a nos deixar saber que eles estão lá.  Os anéis são acreditados como peças de cometas, asteróides ou luas destruídas que se partiram ainda antes de alcançarem o planeta.  Cada anel orbita em uma velocidade diferente em torno ao planeta.  Informação advinda da missão Cassini da Nasa, estará nos ajudando a revelar como os anéis se formaram, como mantêm suas órbitas e, acima de tudo, o porquê de estarem lá, em primeiro lugar.

Enquanto três outros planetas gasosos no sistema solar - Júpiter, Urano e Netuno - possuem anéis orbitando em torno deles, os anéis de Saturno são bem maiores e muito mais espetaculares.  Com uma grossura de cerca de um quilômetro (3.200 pés) ou menos, eles se espraiam até 282.000 quilômetros (175 mil milhas), cerca de três quartos da distância entre a Terra e nossa Lua. 

LEIA MAIS EM 








Montage of Saturn and several of its satellites, Dione, Tethys, Mimas, Enceladus, Rhea, and Titan. JPL image PIA01482: Saturn System Montage This montage of images of the Saturnian system was prepared from an assemblage of images taken by the Voyager 1 spacecraft during its Saturn encounter in November 1980. This artist's view shows Dione in the forefront, Saturn rising behind, Tethys and Mimas fading in the distance to the right, Enceladus and Rhea off Saturn's rings to the left, and Titan in its distant orbit at the top.
Data
Origem
JPL image PIA01482
Autor
NASA



Satélites

Saturno tem um grande número de satélites ou luas, o maior que todos os demais planetas. Os seus maiores satélites, conhecidos antes do começo da exploração espacial, são:MimasEncéladoTétisDioneReiaTitãHipérionJápeto e Febe. O maior desses satélites naturais é Titã, que tem o diâmetro de 5280 quilômetros (maior que o Planeta Mercúrio).
Encélado e Titã são mundos especialmente interessantes para os cientistas planetários, primeiramente pela existência de água líquida a pouca profundidade de sua superfície, com a emissão de vapor da água geyser. Em segundo porque possui uma atmosfera rica do metano, bem similar a da terra primitiva.A sonda Cassini-Huygens em junho de 2004 fotografou o que são considerados mais dois satélites de Saturno, que foram batizados de Methone e Pallene. A 1 de Maio de 2005, um terceiro satélite natural foi descoberto na Falha de Keeler (um intervalo existente no Anel A de Saturno), e foi temporariamente designado de S/2005 S 1. O outro satélite existente dentro do sistema de anéis de Saturno é .
O sistema de satélites maiores de Saturno, que vai até Jápeto, se espalha por cerca de 3,5 milhões de km, enquanto Febe, um satélite menor, faz parte de um sistema de satélites irregulares externos e se localizam a cerca de 12,9 milhões de km do planeta.
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    http://www.esa.int/spaceinimages/Images/2005/02/Shadows_of_Saturn_s_rings_on_the_planet_s_cloud_tops
    • Title Shadows of Saturn's rings on the planet's cloud tops
    • Released 31/01/2004 6:49 pm
    • Copyright NASA/JPL/Space Science Institute
    • DescriptionThe image of ring shadows cast by the Sun on Saturn's surface was taken with the NASA/ESA/ASI Cassini narrow-angle camera on 18 January 2005, at a distance of 1.4 million kilometres from Saturn using a filter sensitive to wavelengths of infrared light centred at 752 nanometres. The image scale is 9 kilometres per pixel.

      Saturn's moon Mimas (398 kilometres across) is seen near the bottom of the frame.
    • Id 205287






    Saturn, the sixth planet from the sun, is home to a vast array of intriguing and unique worlds.
    ................................ 
    Christiaan Huygens discovered the first known moon of Saturn. The year was 1655 and the moon was Titan. Giovanni Domenico Cassini made the next four discoveries:Iapetus (1671), Rhea (1672), Dione (1684), and Tethys(1684). Mimas and Enceladus were both discovered by William Herschel in 1789. The next two discoveries came at intervals of 50 or more years -- Hyperion (1848) and Phoebe (1898).


    Minha (Janine) tradução simples e direta:

    Saturno, o sexto planeta a partir do Sol, acolhe um vasto campo de mundos intrigantes e sem igual.  .........................
    Christiaan Huygens descobriu a primeira conhecida Lua de Saturno.  O ano era 1655 e a Lua era Titan.  Giovanni Domenico Cassini realizou as seguintes quatro descobertas: Iapetus (1671), Rhea (1672), Dione (1684) e Tethys (1684).  Mimas e Enceladus foram ambas descobertas por William Herschel em 1789.  As duas seguintes descobertas vieram em intervalos de 50 ou mais anos - Hyperion (1848) e Phoebe (1898).


    LEIA MAIS, MUITO MAIS,





    As mais importantes Luas de Saturno:


    Saturn: Moons




    In this view captured by NASA's Cassini spacecraft 
    on 13 February 2010, 
    Herschel Crater dominates Mimas,
    making the moon look like the Death Star in the movie "Star Wars."



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    Discovery:
    Mimas was discovered on 17 September 1789 by English astronomer William Herschel, using his 40-foot reflector telescope.

    How Mimas Got its Name:
    The mythological Mimas was a giant who was killed by Mars in the war between the Titans and the gods of Olympus. Even after his death, Mimas' legs -- which were serpents -- hissed vengeance and sought to attack his killer.

    Mimas was named by John Herschel, the son of discoverer William Herschel, who explained his choice of names for the first seven of Saturn's moons to be discovered by writing, "As Saturn devoured his children, his family could not be assembled round him, so that the choice lay among his brothers and sisters, the Titans and Titanesses."

    Saiba mais sobre Mimas,
    acessando









    Enceladus as viewed from NASA's Cassini spacecraft.


    Enceladus [en-SELL-ah-dus] is one of the innermost moons of Saturn. It is quite similar in size to Mimas, but has a smoother, brighter surface. Enceladus reflects almost 100 percent of the sunlight that strikes it. .............................................................................. 
    . It is postulated that Enceladus is heated by a tidal mechanism similar to Jupiter's moon Io. Enceladus is perturbed in its orbit by Saturn's gravitational field and by the large neighboring satellites Tethys and Dione.
    Because Enceladus reflects so much sunlight, the surface temperature is only -330 degrees Fahrenheit (-201degrees Celsius).

    Leia mais sobre Enceladus,
    acessando








    The vast expanse of the crater Odysseus spreads out below Cassini
     in this mosaic view of Saturn's moon Tethys.

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    Tethys appeared as a tiny dot to astronomers until the Voyager (1 and 2) encounters in 1980 and 1981. The Voyager images showed the major impact crater and the great chasm. The Cassini spacecraft has added details including a great variety of colors at small scales suggesting a variety of materials not seen elsewhere.

    Discovery:
    Giovanni Cassini discovered Tethys on 21 March 1684.

    How Tethys Got its Name:
    Cassini referred to Tethys as one of the four Sidera Lodoicea (Stars of Louis) after King Louis XIV (the other three were Iapetus, Dione and Rhea). Other astronomers called the Saturn moons by number in terms of their distance from Saturn. Thus, Tethys was Saturn III. John Herschel suggested that the moons of Saturn be associated with the Greek mythical brothers and sisters of Kronus. (Kronus is the equivalent of the Roman god Saturn in Greek mythology.)
    The name comes from the Greek goddess (or Titan) Tethys, who was the daughter of Uranus and Gaea, a sister to Kronus and the wife of Oceanus. She was said to be the mother of the chief rivers, the mother of three thousand daughters called the Oceanids and the embodiment of the waters of the world.
    Geological features on Tethys generally get their names from "The Odyssey" by Homer. The International Astronomical Union now controls naming of astronomical bodies.

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    The Cassini spacecraft looks down on the north pole of Dione 
    and the fine fractures that cross its trailing hemisphere.



    .....................................

    Dione is in resonance with two nearby moons, Mimas and Enceladus. That is, these moons speed up slightly as they approach each other and slow down as they draw away, causing their orbits to vary slightly in a long series of complex changes, which helps keep them locked in their positions. Dione keeps Enceladus locked at a period exactly one half that of its own orbit.
    Discovery:
    Giovanni Cassini discovered Dione on 21 March 1684.
    How Dione Got its Name:
    Cassini referred to Dione as one of the four Sidera Lodoicea (Stars of Louis) after King Louis XIV (the other three were Iapetus, Tethys and Rhea). Other astronomers called the Saturn moons by number in terms of their distance from Saturn. Thus, Dione was Saturn IV. John Herschel suggested that the moons of Saturn be associated with the Greek mythical brothers and sisters of Kronus. (Kronus is the equivalent of the Roman god Saturn in Greek mythology.) Geological features on Dione generally get their names from people and places in Virgil's "Aeneid." The International Astronomical Union now controls the naming of astronomical bodies.
    The name Dione comes from the Greek goddess (or Titan) Dione, who by some accounts was the daughter of Tethys (who is Kronus' sister) and Oceanus, and who Homer described as the mother of Aphrodite.

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    The trailing hemisphere of Saturn's moon Rhea 
    seen here in natural color, 
    displays bright, wispy terrain 
    that is similar in appearance to that of Dione,
     another one of Saturn's moon.

    ....................................................................

    Rhea appeared as a tiny dot to astronomers until the Voyager (1 and 2) encounters in 1980 and 1981. The Voyager images showed that Rhea's features could be divided into two regions: the first being heavily cratered (bright) terrain with craters larger than 40 km (25 miles) across and a second type of area in parts of the polar and equatorial region with craters less than 40 km across. This difference may indicate there was a major resurfacing event some time in Rhea's history. However, it would have been long ago because there are few young craters with rays extending away from them (as on Earth's Moon), and the average age of the plains is thought to be around four billion years old.

    .............................................
    Discovery:
    Giovanni Cassini discovered Rhea on 23 December 1672.
    How Rhea Got its Name:
    The name Rhea comes from the Greek goddess (or Titan) Rhea, who was the daughter of Uranus and Gaea. Her husband was Kronus (the Roman Saturn). Rhea was also called the mother of the gods because she gave birth to several of the gods of Mount Olympus, including Zeus (the Roman Jupiter).
    Cassini referred to Rhea as one of the four Sidera Lodoicea (Stars of Louis) after King Louis XIV (the other three were Tethys, Dione and Iapetus). Astronomers also refer to Rhea as Saturn V denoting the fifth moon in distance from Saturn. Geological features on Rhea generally get their names from people and places from creation myths. The International Astronomical Union now controls the naming of astronomical bodies.

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    Saturn's moon Tethys with its prominent Odysseus Crater
     silently slips behind Saturn's largest moon Titan.


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    Titan is the biggest of 53 confirmed moons orbiting Saturn (another 9 moons are being confirmed). Titan is a frigid world enveloped by a thick, hazy atmosphere that obscures its surface. Titan has been studied in great detail only in the past few years, with the arrival of the Cassini-Huygens mission at Saturn in 2004.

    Titan is the second largest moon in our solar system, with an equatorial radius of 2,575 km (1,600 miles). It is bigger than Earth's moon, and even larger than the planet Mercury.
    Only Jupiter's moon Ganymede is larger than Titan, with a diameter barely 112 km (62 miles) greater.

    The temperature at Titan's surface is about -178 degrees Celsius (-289 degrees Fahrenheit). At this frigid temperature, water ice is as hard as rock - in fact, most of the rock on Titan's surface is water ice.

    Titan orbits Saturn at a distance of about 1.2 million km (745,000 miles), taking almost 16 days to complete a full orbit.

    Titan is of great interest to scientists because it is the only other place in the solar system known to have an earthlike cycle of liquids flowing across its surface. That Titan has seas of liquid methane was suspected before the first spacecraft flyby, but its opaque atmosphere prevented close inspection even then. In 1980, NASA's Voyager 1 spacecraft tried to take close up images of the natural features of Titan's landscape, but was unable to penetrate the thick clouds. Instead, the images showed only slight color and brightness variations in the atmosphere. Titan's atmospheric pressure is about 60 percent greater than Earth's -- roughly the same pressure found at the bottom of a swimming pool.

    In 1994, NASA's Hubble Space Telescope recorded pictures of Titan, which suggested that a huge bright continent exists on the hemisphere that faces forward in orbit. These Hubble results didn't prove that liquid seas existed, however; only that Titan has large bright and dark regions on its surface.
     ...........................................................

    From Cassini-Huygens, we now know that Titan has lakes and seas of liquid methane (natural gas) and ethane near its poles. These bodies of standing liquids appear to grow and shrink in a seasonal cycle as storms bring rain to one hemisphere, then the other. The mission has revealed drainage channels on the surface that were carved by flowing liquid.
    Cassini's radar instrument revealed that large swaths of the surface near the equator are blanketed by dune fields, similar to the Namibian desert on Earth. The mission has also found that Titan has an internal ocean of liquid water.
    Because of the extremely cold temperatures at Titan's distance from the sun, chemical processes take longer to unfold, leaving the chemistry of the moon's atmosphere in a state of deep freeze. This carbon-rich chemistry is of great interest to scientists because it could be similar to the atmosphere of early Earth, before life emerged on our planet.

    Discovery:
    Titan was discovered on 25 March 1655 by the Dutch astronomer Christiaan Huygens.
    How Titan Got its Name:
    The name Titan comes from a generic term for the children of Ouranos (Uranus) and Gaia in ancient Greek mythology. In the stories, the Titans were the ancestors of the human race. The Titans were known to have devoured the limbs of Dionysus, the son of Zeus. Enraged, Zeus struck the Titans with lightning. (Zeus had intended this child to have dominion over the world.) The lightning burned the Titans to ashes, and from the ashes, mankind was formed.

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    This stunning false-color view of Saturn's moon Hyperion
     reveals crisp details across the strange, tumbling moon's surface. 
    Differences in color could represent differences in the composition of surface materials. 
    The view was obtained during Cassini's very close flyby on 26 September 2005.



    Discovery:
    William Lassell discovered Hyperion in 1848. That same year William Cranch Bond, with his son George Phillips Bond, independently discovered the moon. All three men are jointly credited with the discovery.

    How Hyperion Got its Name:
    John Herschel suggested that the moons of Saturn be associated with the mythical brothers and sisters of Kronus. (Kronus is the equivalent of the Roman god Saturn in Greek mythology.)
    The name Hyperion comes from the Greek god (or Titan) Hyperion (he who watches over). Hyperion is the son of Uranus and Gaia, a brother of Kronus and the husband of Thea. The children of Hyperion and Thea include Helios (the sun), Eos (the dawn) and Selene (the Moon).

    Saiba mais acessando






    This false-color mosaic shows the entire hemisphere of Iapetus
    visible from Cassini on the outbound leg
     of its encounter with the two-toned moon in September 2007.

    Iapetus [pronounced eye-APP-eh-tuss; adjective form: Iapetian] has been called the yin and yang of the Saturn moons because its leading hemisphere has a reflectivity (or albedo) as dark as coal (albedo 0.03-0.05 with a slight reddish tinge) and its trailing hemisphere is much brighter at 0.5-0.6.

    Giovanni Cassini observed the dark-light difference when he discovered Iapetus in 1671. He noted that he could only see Iapetus on the west side of Saturn. He correctly concluded that Iapetus had one side much darker than the other side, and that Iapetus was tidally locked with Saturn.

    Scientists have long wondered why one hemisphere of Iapetus is so dark in comparison to its other hemisphere, and in comparison to other surfaces in the Saturn system. Iapetus may be sweeping up particles from the more-distant dark moon, Phoebe. If that is the darkening mechanism, it should be steadily renewing the dark surface because very few fresh bright craters are detected within the dark terrain. An alternate theory is that there might be ice volcanism distributing darker material to the surface. Volcano-like eruptions of hydrocarbons might form the dark surfaces, particularly after chemical reactions caused by solar radiation.
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    Discovery:
    Giovanni Cassini discovered Iapetus on 25 October 1671. However, Iapetus appeared only as a bright, dark dot to astronomers until the Voyager I and Voyager II encounters in 1980 and 1981.
    How Iapetus Got its Name:
    John Herschel suggested that the moons of Saturn be associated with the mythical brothers and sisters of Kronus. (Kronus is the equivalent of the Roman god Saturn in Greek mythology.)
    The name Iapetus comes from the Greek god (or Titan) Iapetus, who is a son of Uranus and Gaia, a brother to Kronus and the father of Atlas and Prometheus. As the father of Prometheus, the ancient Greeks regarded Iapetus as the father of the human race.
    Cassini referred to Iapetus as one of the four Sidera Lodoicea (Stars of Louis) after King Louis XIV (the other three were Tethys, Dione and Rhea). Other astronomers called Iapetus by its number in the order of moons discovered at the time. Iapetus started as Saturn V, and it became Saturn VIII after additional moons were discovered. Geological features on Iapetus generally get their names from the French epic poem "The Song of Roland."

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    Cassini captured this detailed view of Phoebe in 2004.


    Phoebe is one of Saturn's most intriguing satellites, orbiting at a distance of 12,952,000 km (8,049,668 miles) from the planet, almost four times the distance from Saturn than its nearest neighbor, the moon Iapetus. Phoebe and Iapetus are the only major moons in the Saturnian system that do not orbit closely to the plane of Saturn's equator.

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    Discovery
    Phoebe was discovered August 1898 by American astronomer William Pickering.

    How Phoebe Got its Name
    Moons of Saturn were originally named for Greco-Roman Titans and descendants of the Titans. But as many new moons were discovered scientists began selecting names from more mythologies, including Gallic, Inuit and Norse stories.

    Phoebe (FEE-bee) is another name for the goddess that the Greeks called Artemis and the Romans called Diana. She was the youthful goddess of Earth's Moon, forests, wild animals, and hunting. Sworn to chastity and independence, she never married and was closely identified with her brother Apollo.

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    LEIA MAIS, MUITO MAIS
    SOBRE AS LUAS ACIMA APRESENTADAS
    E SOBRE AS DEMAIS LUAS DE SATURNO,
    ACESSANDO
    http://solarsystem.nasa.gov/planets/profile.cfm?Object=Saturn&Display=Sats