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The Jovian Planets
•Jupiter•Saturn•Uranus•Neptune
Saturn seen by Cassini
Gas Giant SizesGas Giant Sizes
http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=180
Jupiter DataJupiter Data
Mean Distance from SunMean Distance from Sun483,300,000 miles 483,300,000 miles
5.2 AU5.2 AU
Diameter at the EquatorDiameter at the Equator88,700 miles88,700 miles
Length of “Year” Length of “Year” (revolution (revolution around the sun)around the sun)
11.86 earth years11.86 earth years
Diameter if Earth = 1Diameter if Earth = 111.1911.19
Length of “Day”Length of “Day”9 hr. 50 min. 30 sec.9 hr. 50 min. 30 sec.
Mass if Earth = 1Mass if Earth = 1317.83 317.83
SymbolSymbol
Surface Gravity if Earth = 1Surface Gravity if Earth = 12.54 2.54
http://www.vegaattractions.com/astrology/symbols.html
King PlanetKing Planet
King of the GodsKing of the Gods: Jupiter (Greek, Zeus) : Jupiter (Greek, Zeus) was the King of the Gods. Jupiter was the was the King of the Gods. Jupiter was the son of Saturn (Greek, Cronus)son of Saturn (Greek, Cronus)
Jupiter is the largest planet in the solar Jupiter is the largest planet in the solar systemsystem
1,400 planet earths would fill Jupiter1,400 planet earths would fill JupiterSome of Jupiter’s moons are larger than Some of Jupiter’s moons are larger than
recognized planetsrecognized planets
DiscoveryDiscovery: Jupiter is the fourth brightest object in the : Jupiter is the fourth brightest object in the sky after the sun, moon, and Venus (sometimes sky after the sun, moon, and Venus (sometimes Mars is brighter than Jupiter). Mars is brighter than Jupiter).
Galileo discovered Jupiter’s four largest moons in Galileo discovered Jupiter’s four largest moons in 1610 (Io, Europa, Ganymede, Callisto)1610 (Io, Europa, Ganymede, Callisto)
These are referred to as the Galilean moonsThese are referred to as the Galilean moons Galilean moons are visible in binoculars and small Galilean moons are visible in binoculars and small
telescopestelescopes Moons are in different positions each nightMoons are in different positions each night
DiscoveryDiscovery
Galileo’s Galileo’s SketchesSketches
http://antwrp.gsfc.nasa.gov/apod/image/0110/
Galileo’s telescopes
Jupiter’s SatellitesJupiter’s Satellites
www.skyandtelescope.com
•The chart shows the revolutions of Jupiter’s moons
•Along the side are the days of the month
•Visualize a line crossing the chart, the positions where the line crosses the spirals represent the appearance of Jupiter’s moons for that date
•The closest satellite Io forms the smallest spiral pattern
•The farthest satellite from Jupiter, Callisto, forms the largest spiral
Fastest DayFastest Day
Rapid RotationRapid Rotation: One Jupiter day is equal : One Jupiter day is equal to nearly 10 earth hours—the shortest to nearly 10 earth hours—the shortest “day” in the solar system. “day” in the solar system.
Features on Jupiter appear to move Features on Jupiter appear to move quickly when seen in a telescopequickly when seen in a telescope
Rapid rotation creates a squashed Rapid rotation creates a squashed appearanceappearance
Missions to JupiterMissions to Jupiter
SpacecraftSpacecraft: Pioneer 10 in 1973 and later : Pioneer 10 in 1973 and later by Pioneer 11, Voyager 1, and Voyager 2by Pioneer 11, Voyager 1, and Voyager 2
Galileo mission orbited Jupiter for many Galileo mission orbited Jupiter for many years (1995—2003)years (1995—2003)
Galileo plunged into Jupiter's crushing Galileo plunged into Jupiter's crushing atmosphere on Sept. 21, 2003atmosphere on Sept. 21, 2003
Gas GiantGas Giant
Gas PlanetGas Planet: Jupiter does not have a solid : Jupiter does not have a solid surface. surface.
We see the top of Jupiter’s atmosphereWe see the top of Jupiter’s atmosphere Jupiter is about 90% hydrogen and 10% Jupiter is about 90% hydrogen and 10%
helium. helium. Similar to the composition of the nebula Similar to the composition of the nebula
from which the sun and planets formed. from which the sun and planets formed. Jupiter may have a solid coreJupiter may have a solid core Jupiter radiates more heat back into space Jupiter radiates more heat back into space
than it receives from the sunthan it receives from the sun
Differential RotationDifferential Rotation
Jupiter’s rotation rate varies with latitude Jupiter’s rotation rate varies with latitude (differential rotation)(differential rotation)
The other gas planets, and the sun, also The other gas planets, and the sun, also display differential rotationdisplay differential rotation
POLAR REGION ROTATION TIME
9 hours 55minutes
EQUATORIAL REGION ROTATION TIME
9hours 50minutes
Jupiter’s Differential RotationJupiter’s Differential Rotation
Cloud BandsCloud Bands
Jupiter has high velocity winds (up to 400 Jupiter has high velocity winds (up to 400 mph) confined in wide latitude bandsmph) confined in wide latitude bands
The winds blow in opposite directions in The winds blow in opposite directions in nearby bands nearby bands
Colors related to composition and tempColors related to composition and tempZonesZones: Light colored bands: Light colored bandsBeltsBelts: Dark colored bands : Dark colored bands
Jupiter’s clouds move in east-west bandsJupiter’s clouds move in east-west bands
Reddish-colored belts alternate with white-colored zones.
Zones & Belts of JupiterZones & Belts of Jupiter
Great Red SpotGreat Red Spot
Great Red SpotGreat Red Spot: First observed > 300 : First observed > 300 years ago years ago
The GRS is an oval about 7,500 by 15,500 The GRS is an oval about 7,500 by 15,500 miles, big enough to hold two earths.miles, big enough to hold two earths.
Essentially a region of low pressure, a Essentially a region of low pressure, a stormstorm
Jupiter & GanymedeJupiter & Ganymede
Voyager’s Great Red SpotVoyager’s Great Red Spot
http://antwrp.gsfc.nasa.gov/apod/image/0202/jupredspot_vg2_big.jpg
Jupiter’s MagnetismJupiter’s Magnetism
MagnetosphereMagnetosphere: Jupiter has an immense : Jupiter has an immense magnetic field, much stronger than that of magnetic field, much stronger than that of earth.earth.
It is so large that Jupiter’s moons lie within It is so large that Jupiter’s moons lie within this magnetic zone. this magnetic zone.
Field traps dangerous radiation Field traps dangerous radiation Creates massive auroras, imaged by HSTCreates massive auroras, imaged by HST
Jupiter’s MagnetosphereJupiter’s Magnetosphere
http://www.boulder.swri.edu/~spencer/jupmag5na.jpg
Jovian AurorasJovian Auroras
http://www.eso.org/outreach/eduoff/edu-prog/catchastar/CAS2002/cas-projects/porto_jupiter_1/jupiteraurora2.jpg
Another Ringed PlanetAnother Ringed Planet
Jupiter has a faint ring systemJupiter has a faint ring systemDiscovered by the Voyager spacecraftDiscovered by the Voyager spacecraftAll of the Jovian planets possess ring All of the Jovian planets possess ring
systems (Jupiter, Saturn, Uranus, systems (Jupiter, Saturn, Uranus, Neptune)Neptune)
Galileo Mission: Jupiter’s RingsGalileo Mission: Jupiter’s Rings
http://pds-rings.seti.org/jupiter/
The Jupiter CometThe Jupiter Comet Shoemaker-Levy 9Shoemaker-Levy 9: In July 1994, Comet Shoemaker-: In July 1994, Comet Shoemaker-
Levy 9 collided with Jupiter.Levy 9 collided with Jupiter. Discovered in advanceDiscovered in advance Impact observed by the Hubble Space Telescope and Impact observed by the Hubble Space Telescope and
other instrumentsother instruments Jupiter captured the comet into a new orbitJupiter captured the comet into a new orbit Comet broke into pieces, each fragment creating a Comet broke into pieces, each fragment creating a
separate impactseparate impact Dark spots created by this collision were visible even in Dark spots created by this collision were visible even in
small telescopes and lasted almost one year. small telescopes and lasted almost one year. One of the rarest observations in scienceOne of the rarest observations in science
Impact!Impact!
http://www.solarviews.com/raw/sl9/
Hubble Space Telescope ViewHubble Space Telescope View
http://nssdc.gsfc.nasa.gov/planetary/sl9/image/sl9g_hst5.gif
SL-9’s Dark Spots (HST)SL-9’s Dark Spots (HST)
http://antwrp.gsfc.nasa.gov/apod/image/9808/sl9gevol_hst_big.jpg
Jupiter’s SatellitesJupiter’s Satellites
Jupiter has 63 known satellites (As of Jupiter has 63 known satellites (As of 2004), the 4 large Galilean moons and 59 2004), the 4 large Galilean moons and 59 small ones. small ones.
Named for characters in the mythology of Named for characters in the mythology of Jupiter Jupiter
SatellitesSatellites
MetisMetis IoIo LedaLeda AnankeAnanke
AdrastaeAdrastae EuropaEuropa HimaliaHimalia CarmeCarme
AmaltheaAmalthea GanymedeGanymede LysitheaLysithea PasiphaePasiphae
ThebeThebe CallistoCallisto ElaraElara SinopeSinope
Jupiter’s first 16 satellites (in order outward from Jupiter)
Galilean Satellites
Moons of the Solar SystemMoons of the Solar System
Galilean SatellitesGalilean Satellites: Io: Io
IoIo is the third largest satellite of Jupiter is the third largest satellite of Jupiter Io is slightly larger than earth’s moonIo is slightly larger than earth’s moon
Io’s SurfaceIo’s Surface
Io displays a young, dynamic, rocky Io displays a young, dynamic, rocky surface. surface.
The Voyager 1 discovered areas of active The Voyager 1 discovered areas of active volcanism, the first ever discovered on volcanism, the first ever discovered on another worldanother world
Io’s volcanoes erupt molten sulfurIo’s volcanoes erupt molten sulfur
Io’s FeaturesIo’s Features
Volcanic surface features such as Volcanic surface features such as calderas, lakes of molten sulfur, flows of calderas, lakes of molten sulfur, flows of molten sulfur hundreds of miles long, and molten sulfur hundreds of miles long, and volcanic ventsvolcanic vents
Sulfur and its compounds are colorfulSulfur and its compounds are colorful Io most resembles a cheese pizzaIo most resembles a cheese pizza Io’s volcanism most likely results from Io’s volcanism most likely results from
Jupiter’s tidal actionJupiter’s tidal action
Io’s Hellish Surface (Galileo)Io’s Hellish Surface (Galileo)
http://www.solarviews.com/browse/jup/
Io VolcanismIo Volcanism
http://archives.cnn.com/2001/TECH/space/02/27/
Io and Jupiter’s Clouds Io and Jupiter’s Clouds (Cassini)(Cassini)
http://www.spacedaily.com/images/cassini-galileo-jupiter-io-desk.jpg
Io by Cassini
Galilean Satellites: EuropaGalilean Satellites: Europa
Europa is fourth largest satellite of JupiterEuropa is fourth largest satellite of JupiterEuropa is slightly smaller than the earth’s Europa is slightly smaller than the earth’s
moon.moon.
Europa’s SurfaceEuropa’s Surface
SurfaceSurface: Smooth, frozen water surface: Smooth, frozen water surfaceYoung, very few apparent impact cratersYoung, very few apparent impact cratersResembles a billiard ballResembles a billiard ball
Europa’s WaterEuropa’s Water
Liquid WaterLiquid Water: Europa’s surface resembles : Europa’s surface resembles sea ice on earthsea ice on earth
Europa might posses an internal layer of Europa might posses an internal layer of liquid water, perhaps as much as 30 miles liquid water, perhaps as much as 30 miles deepdeep
Liquid water is an important ingredient for Liquid water is an important ingredient for lifelife
Dark StreaksDark Streaks
Dark StreaksDark Streaks: Dark streaks crisscross the : Dark streaks crisscross the entire globe of the satelliteentire globe of the satellite
The larger ones are roughly 12 miles The larger ones are roughly 12 miles across.across.
EuropaEuropa
http://www.pa.msu.edu/people/horvatin/Images/Planets/jupiter/Europa.jpg
Europa-SurfacesEuropa-Surfaces
http://www.astro.psu.edu/users/niel/astro1/slideshows/class41/014-europa-surfaces.jpg
Dark Streaks on EuropaDark Streaks on Europa
http://www.personal.psu.edu/users/p/e/pew114/After%20we%20travel%20to%20Jupiter%20Red%20Spot_files/image003.jpg
Ski Ski Europa!Europa!
http://www.cita.utoronto.ca/~murray/GLG130/Pictures/Jupiter/Europa_flow.jpg
Dive Europa!Dive Europa!
http://www.planetengrund.com/bilder/Europa-Orbiter-Mission-Hydr.jpg
http://astrobiology.arc.nasa.gov/feature/europa_ocean.jpg
Galilean Satellites: GanymedeGalilean Satellites: Ganymede
Ganymede is the largest of Jupiter’s Ganymede is the largest of Jupiter’s known satellites, and the largest satellite in known satellites, and the largest satellite in the solar system. the solar system.
Ganymede is larger than Mercury and Ganymede is larger than Mercury and PlutoPluto
Ganymede’s SurfaceGanymede’s Surface
Icy SurfaceIcy Surface: Old, icy surface: Old, icy surfacePossesses numerous impact cratersPossesses numerous impact cratersThe craters on Ganymede are thought to The craters on Ganymede are thought to
date from 3 billion years in the past, similar date from 3 billion years in the past, similar to earth’s moonto earth’s moon
Ganymede also exhibits light colored Ganymede also exhibits light colored grooves and ridgesgrooves and ridges
Ganymede’s CratersGanymede’s Craters
Formed in iceFormed in iceCrater walls slump over time creating Crater walls slump over time creating
“ghost” craters termed palimpsests. “ghost” craters termed palimpsests.
GanymedeGanymede
http://antwrp.gsfc.nasa.gov/apod/image/
Ganymede TerrainGanymede Terrain
http://www.lpi.usra.edu/resources/outerp/gct.gif
Enki Catena (crater chain)Enki Catena (crater chain)
http://neo.jpl.nasa.gov/images/ganymede.html
Galilean Satellites: CallistoGalilean Satellites: Callisto
Callisto is the second largest Jupiter Callisto is the second largest Jupiter satellitesatellite
Slightly smaller than the planet MercurySlightly smaller than the planet MercuryCallisto is about 40% ice and 60% rock Callisto is about 40% ice and 60% rock
and ironand iron
Callisto’s SurfaceCallisto’s Surface
SurfaceSurface: Ancient surface, saturated with : Ancient surface, saturated with craterscraters
Resembles highlands on the moon and Resembles highlands on the moon and MarsMars
Possibly the oldest unaltered surface in Possibly the oldest unaltered surface in the solar systemthe solar system
CallistoCallisto
Galileo Probe: Callisto terrain
http://www.astrophys-assist.com/educate/robot/images/
Galileo: Callisto TerrainGalileo: Callisto Terrain
ValhallaValhalla
Valhalla is a gigantic, multi-ring impact Valhalla is a gigantic, multi-ring impact basin nearly 1,900 miles in diameterbasin nearly 1,900 miles in diameter
Resembles a bull’s eyeResembles a bull’s eyeSimilar to Mare Orientale on the moon, Similar to Mare Orientale on the moon,
and Mercury’s Caloris Basinand Mercury’s Caloris Basin
ValhallaValhalla
http://cseligman.com/text/moons/callisto.htm
Gipul CatenaGipul Catena
A chain of impact cratersA chain of impact cratersA series of impacts from a fragmented A series of impacts from a fragmented
bodybodySimilar to the Shoemaker-Levy 9 comet Similar to the Shoemaker-Levy 9 comet
impactimpact
Gipul CatenaGipul Catena
http://www.lpi.usra.edu/resources/outerp/cc2.gif
Jupiter FamilyJupiter Family
Left to Right: Ganymede, Callisto, Io, Europa
Lore of JupiterLore of Jupiter
A conjunction of Jupiter and Venus in the A conjunction of Jupiter and Venus in the year 3 B.C. may have been the inspiration year 3 B.C. may have been the inspiration for the famous Star of Bethlehemfor the famous Star of Bethlehem
Venus and Jupiter appeared to merge Venus and Jupiter appeared to merge briefly, would have appeared as one briefly, would have appeared as one incredibly bright starincredibly bright star
Star of Bethlehem?Star of Bethlehem?
http://www.go.ednet.ns.ca/~larry/planets/west_2bc.gif
Saturn Saturn
Saturn DataSaturn Data
Mean Distance from SunMean Distance from Sun886,281,264 miles 886,281,264 miles
8.8 AU8.8 AU
Diameter at the EquatorDiameter at the Equator74,600 miles74,600 miles
Length of Year Length of Year 29.46 earth years29.46 earth years
Diameter if Earth = 1Diameter if Earth = 19.419.41
Length of DayLength of Day10 hr, 14 min10 hr, 14 min
Mass if Earth = 1Mass if Earth = 195.16 95.16
SymbolSymbol (draw) (draw)
Surface Gravity if Earth = 1Surface Gravity if Earth = 11.081.08
http://www.vegaattractions.com/images/1saturn.gif
Ringed PlanetRinged Planet
Saturn has been known since prehistoric timesSaturn has been known since prehistoric times It is visible to the naked eye and resembles a It is visible to the naked eye and resembles a
bright, yellow star that doesn’t twinkle bright, yellow star that doesn’t twinkle Saturn is most famous for its system of rings. Saturn is most famous for its system of rings.
Galileo first observed Saturn with a telescope in Galileo first observed Saturn with a telescope in 1610 1610
Galileo was unable to see the rings, he thought Galileo was unable to see the rings, he thought that the planet had two large satellites that the planet had two large satellites resembling ears, a Mickey Mouse worldresembling ears, a Mickey Mouse world
Cassini: Approaching SaturnCassini: Approaching Saturn
Huygens’ RingsHuygens’ Rings
Christian Huygens first correctly described Christian Huygens first correctly described the rings of Saturn in 1659 the rings of Saturn in 1659
Saturn’s rings remained unique in the Saturn’s rings remained unique in the solar system until the 1970’s when faint solar system until the 1970’s when faint rings were discovered around Jupiter, rings were discovered around Jupiter, Uranus, and Neptune Uranus, and Neptune
http://www.phaenomen.de/deutsch/geschichte/assets/auto_generated_images/img_462b4b421.gif
Huygens Discovered Saturn’s Huygens Discovered Saturn’s RingsRings
http://www2.jpl.nasa.gov/saturn
Huygens sketch
Huygens loooong refracting telescope
Saturn’s VisibilitySaturn’s Visibility From earth, Saturn appears to slowly drift through the From earth, Saturn appears to slowly drift through the
zodiac constellations requiring 29 earth years for one zodiac constellations requiring 29 earth years for one complete revolutioncomplete revolution
Throughout its 29 year revolution, Saturn’s orientation Throughout its 29 year revolution, Saturn’s orientation allows us to see the top and bottom of the rings, each allows us to see the top and bottom of the rings, each half is visible for about 14 earth yearshalf is visible for about 14 earth years
When Saturn appears edge on, the rings appear as a When Saturn appears edge on, the rings appear as a thin line and nearly disappear. This is termed a thin line and nearly disappear. This is termed a ring-ring-plane crossingplane crossing. The last occurred in 1995, we are due for . The last occurred in 1995, we are due for another in 2009another in 2009
Saturn’s synodic period is a little over an earth year long Saturn’s synodic period is a little over an earth year long (378 days), this means that Saturn’s oppositions occur (378 days), this means that Saturn’s oppositions occur every 378 daysevery 378 days
Our view of Saturn’s rings during its 30-year Our view of Saturn’s rings during its 30-year revolution around the Sunrevolution around the Sun
At some points in its orbit, we see the full face of the rings, and sometimes the rings disappear when we see them edge-on.
Saturn’s Changing Inclination Saturn’s Changing Inclination (Friedman, 2004-2007)(Friedman, 2004-2007)
http://www.spaceweather.com/swpod2007/09feb07/friedman.gif
Saturn Ring Plane CrossingSaturn Ring Plane Crossing
Full Moon & SaturnFull Moon & Saturn
Missions to SaturnMissions to Saturn
Saturn was first visited by NASA's Pioneer 11 in Saturn was first visited by NASA's Pioneer 11 in 1979 and later by Voyager 1 and Voyager 21979 and later by Voyager 1 and Voyager 2
Cassini (a joint NASA / ESA project) arrived on Cassini (a joint NASA / ESA project) arrived on July 1, 2004 and orbits SaturnJuly 1, 2004 and orbits Saturn
Cassini released the Huygens probe that landed Cassini released the Huygens probe that landed on Saturn’s moon Titan in January 2005on Saturn’s moon Titan in January 2005
Huygens was able to return images from the Huygens was able to return images from the surface of Titansurface of Titan
Fast RotatorFast Rotator
Like Jupiter, Saturn has a fast rotation of Like Jupiter, Saturn has a fast rotation of close to 10 hours on earth close to 10 hours on earth
Lightest PlanetLightest Planet: Saturn is the least dense : Saturn is the least dense of the planets, it is less dense than liquid of the planets, it is less dense than liquid waterwater
Like Jupiter, Saturn is composed of gases, Like Jupiter, Saturn is composed of gases, there is no solid surface except perhaps at there is no solid surface except perhaps at the very center where a solid core is the very center where a solid core is thought to existthought to exist
The Lightest PlanetThe Lightest Planet
Saturn is about 75% hydrogen and 25% Saturn is about 75% hydrogen and 25% helium helium
Similar in composition to the supposed Similar in composition to the supposed nebula from which the solar system nebula from which the solar system formedformed
As does Jupiter, Saturn emits more heat As does Jupiter, Saturn emits more heat back into space than it receives from the back into space than it receives from the sunsun
Cloud FeaturesCloud Features
Unlike Jupiter, Saturn’s zones and belts Unlike Jupiter, Saturn’s zones and belts are more difficult to see. are more difficult to see.
Saturn displays white oval spots on rare Saturn displays white oval spots on rare occasions. occasions.
Cassini: Swirling Storms of Cassini: Swirling Storms of SaturnSaturn
Ring FeaturesRing Features
The major divisions of The major divisions of Saturn’s rings are Saturn’s rings are named A, B, and Cnamed A, B, and C
The gap between the The gap between the A and B rings is A and B rings is named the Cassini named the Cassini division.division.
A
B
C
Cassini Division
Saturn’s FeaturesSaturn’s Features
Ring ParticlesRing Particles
Rings appear solid in a small Rings appear solid in a small telescopetelescope
Actually made of many small Actually made of many small particles each in an independent particles each in an independent revolution about Saturn. revolution about Saturn.
Particles range from less than an Particles range from less than an inch to several yardsinch to several yards
Each particle a separate “moon” of Each particle a separate “moon” of SaturnSaturn
Cassini: Saturn’s Rings Cassini: Saturn’s Rings
Amorphous RingsAmorphous Rings
Rings: 155,376 miles in diameter, but are Rings: 155,376 miles in diameter, but are less than a mile in thickness. less than a mile in thickness.
All ring particles squeezed together would All ring particles squeezed together would create a world < 60 miles acrosscreate a world < 60 miles across
Ring particles mainly water ice with some Ring particles mainly water ice with some rock rock
Ring OriginsRing Origins: Probably the breakup of : Probably the breakup of some larger satellitessome larger satellites
Cassini Spacecraft Crosses Cassini Spacecraft Crosses
Saturn's Ring PlaneSaturn's Ring Plane
Satellites of SaturnSatellites of Saturn
Saturn has 34 named satellites [click]Saturn has 34 named satellites [click]The first satellites were discovered by The first satellites were discovered by
telescopic observers. Later satellites were telescopic observers. Later satellites were discovered by space missionsdiscovered by space missions
Saturn’s satellites were named for Saturn’s satellites were named for miscellaneous Greek and Roman miscellaneous Greek and Roman mythological charactersmythological characters
Saturn’s first known moon was Titan, Saturn’s first known moon was Titan, discovered in 1655 by Christian Huygensdiscovered in 1655 by Christian Huygens
First 18 Satellites of SaturnFirst 18 Satellites of Saturn
PanPan MimasMimas HeleneHelene
AtlasAtlas EnceladusEnceladus RheaRhea
PrometheusPrometheus TethysTethys TitanTitan
PandoraPandora TelestoTelesto HyperionHyperion
EpimetheusEpimetheus CalypsoCalypso IapetusIapetus
JanusJanus DioneDione PhoebePhoebe
Some Mythology of Saturn’s Some Mythology of Saturn’s MoonsMoons
PanPan: Half human, half goat Roman god: Half human, half goat Roman godPandoraPandora: Made of clay by Hephaestus at : Made of clay by Hephaestus at
the request of Zeus; she married the request of Zeus; she married Epimetheus and opened the box that Epimetheus and opened the box that loosed a host of plagues upon humanityloosed a host of plagues upon humanity
MimasMimas: A Titan felled by Hephaestus in : A Titan felled by Hephaestus in the war between the Titans and Olympian the war between the Titans and Olympian gods. gods.
MimasMimas
Mimas is composed mainly of water ice and a Mimas is composed mainly of water ice and a small amount of rock. small amount of rock.
The surface of Mimas is dominated by an impact The surface of Mimas is dominated by an impact crater 80 miles in diameter. This crater is almost crater 80 miles in diameter. This crater is almost 1/3 of the diameter of Mimas. 1/3 of the diameter of Mimas.
This crater is named Herschel after William This crater is named Herschel after William Herschel, the astronomer who discovered Herschel, the astronomer who discovered Mimas in 1789. Mimas in 1789.
The rest of Mimas is saturated with craters.The rest of Mimas is saturated with craters.
Darth Crater on Mimas Darth Crater on Mimas
EnceladusEnceladus
EnceladusEnceladus is the most reflective body of is the most reflective body of any in the solar system. Its surface is any in the solar system. Its surface is covered with fresh, clean ice. covered with fresh, clean ice.
Enceladus exhibits smooth plains and liner Enceladus exhibits smooth plains and liner cracks (tiger stripes) and ridges. cracks (tiger stripes) and ridges.
Much of the surface appears to be Much of the surface appears to be geologically young (lacking craters)geologically young (lacking craters)
20052005: Cassini imaged fountains of water : Cassini imaged fountains of water iceice
Fresh Tiger Stripes on Saturn's Enceladus Fresh Tiger Stripes on Saturn's Enceladus
Enceladus Close-Up Enceladus Close-Up
Fountains of EnceladusFountains of Enceladus
TitanTitan Titan is the largest satellite of Saturn, larger in Titan is the largest satellite of Saturn, larger in
diameter than Mercury and Plutodiameter than Mercury and Pluto Titan is the second largest satellite in the solar Titan is the second largest satellite in the solar
system (after Ganymede).system (after Ganymede). Titan is about half water ice and half rocky Titan is about half water ice and half rocky
material. material. Titan has a thick, orange atmosphere of nitrogenTitan has a thick, orange atmosphere of nitrogen The Cassini mission landed a probe (Huyghens) The Cassini mission landed a probe (Huyghens)
on the surface of Titan in 2004on the surface of Titan in 2004 Cassini observed stream patterns and Cassini observed stream patterns and
shorelines, likely liquid methaneshorelines, likely liquid methane
Cassini’s TitanCassini’s Titan
Three Kilometers Above Titan Three Kilometers Above Titan
Titan’s Surface Titan’s Surface (Huygens)(Huygens)
http://www.esa.int/SPECIALS/Cassini-Huygens/SEM15Y71Y3E_1.html
Shoreline Terrain on Saturn's TitanShoreline Terrain on Saturn's Titan
(Huygens Probe)(Huygens Probe)
Titan: Stream BedsTitan: Stream Beds
Huyghens Landing MovieHuyghens Landing Movie
[Click]
Hyperion: Sponge Moon of Saturn Hyperion: Sponge Moon of Saturn
IapetusIapetus
Iapetus is the third largest of Saturn’s Iapetus is the third largest of Saturn’s moons moons
One hemisphere of Iapetus is as dark as One hemisphere of Iapetus is as dark as coal, and the other half is brightcoal, and the other half is bright
Resembles yin & yangResembles yin & yangCassini imaged strange equatorial Cassini imaged strange equatorial
mountain range, moon resembles a walnutmountain range, moon resembles a walnut
Saturn's Iapetus: Moon with a Strange Saturn's Iapetus: Moon with a Strange Surface Surface
http://starryskies.com/solar_system/saturn/iapetus.jpg
Lore of SaturnLore of Saturn
CronusCronus: Saturn, as the outermost of the : Saturn, as the outermost of the classical planets, requires the longest time classical planets, requires the longest time to revolve once around the sun (about 30 to revolve once around the sun (about 30 years). years).
Therefore, the Greek god Cronus (Roman Therefore, the Greek god Cronus (Roman Saturn) was believed to be lethargic and Saturn) was believed to be lethargic and have a dark personality. have a dark personality.
The term The term saturninesaturnine means means uncommunicative, melancholy, and slow.uncommunicative, melancholy, and slow.
Uranus DataUranus Data
Mean Distance from SunMean Distance from Sun1,782,000,000 miles1,782,000,000 miles
19.2 AU19.2 AU
Diameter at the EquatorDiameter at the Equator31,800 miles31,800 miles
Length of “Year” Length of “Year” (revolution (revolution around the sun)around the sun)
84.01 earth years84.01 earth years
Diameter if Earth = 1Diameter if Earth = 14.014.01
Length of “Day”Length of “Day”17 hr. 14 min.17 hr. 14 min.
Mass if Earth = 1Mass if Earth = 114.5 14.5
SymbolSymbol
Surface Gravity if Earth = 1Surface Gravity if Earth = 10.91 0.91
First New PlanetFirst New Planet
UranusUranus: Uranus is the ancient Greek deity : Uranus is the ancient Greek deity of the heavensof the heavens
Uranus was the son of Gaia (earth) and Uranus was the son of Gaia (earth) and the father of Cronus (Saturn)the father of Cronus (Saturn)
First Modern PlanetFirst Modern Planet: Uranus was the first : Uranus was the first planet to be discovered in modern timesplanet to be discovered in modern times
William Herschel discovered Uranus on William Herschel discovered Uranus on March 13, 1781March 13, 1781
Observing UranusObserving Uranus
Uranus is sometimes just barely visible to Uranus is sometimes just barely visible to the unaided eye on a very clear nightthe unaided eye on a very clear night
It is easy to locate with binoculars if you It is easy to locate with binoculars if you know exactly where to lookknow exactly where to look
In a telescope, the planet resembles a In a telescope, the planet resembles a tiny, green-colored disktiny, green-colored disk
Blue Gas GiantBlue Gas Giant
Uranus is a gas giant like Jupiter and Uranus is a gas giant like Jupiter and Saturn Saturn
The atmosphere of Uranus is composed of The atmosphere of Uranus is composed of 83% hydrogen, 15% helium, and 2% 83% hydrogen, 15% helium, and 2% methanemethane
The methane creates the blue color of The methane creates the blue color of Uranus’s atmosphereUranus’s atmosphere
Uranus From Earth (Keck)Uranus From Earth (Keck)
http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=3163
Voyager 2Voyager 2
SpacecraftSpacecraft: Uranus has been visited by : Uranus has been visited by only one spacecraft, Voyager 2 on Jan 24, only one spacecraft, Voyager 2 on Jan 24, 1986. 1986.
Voyager revealed Uranus to be a Voyager revealed Uranus to be a featureless blue disk of gas. featureless blue disk of gas.
Voyager also discovered 10 small moons Voyager also discovered 10 small moons in addition to the 5 large ones already in addition to the 5 large ones already known. known.
Planet on Its SidePlanet on Its Side
Tilted PlanetTilted Planet: The rotational axis of Uranus : The rotational axis of Uranus is tilted 98º is tilted 98º
The planet appears to be lying on its side. The planet appears to be lying on its side. Each pole of the planet is pointed towards Each pole of the planet is pointed towards
the sun for about 42 years, half of a the sun for about 42 years, half of a “Uranian” year. “Uranian” year.
Why is Uranus tilted so dramatically? The Why is Uranus tilted so dramatically? The planet may have suffered a collision with planet may have suffered a collision with an earth-sized object early in its formationan earth-sized object early in its formation
The Uranus axis of rotation is tilted on its side, making seasonal changes drastic.
Axial Tilts of the PlanetsAxial Tilts of the Planets
Dark RingsDark Rings
RingsRings: A faint system of rings was : A faint system of rings was discovered in 1977 when Uranus passed discovered in 1977 when Uranus passed in front of a star. in front of a star.
Voyager 2 photographed the rings in 1986. Voyager 2 photographed the rings in 1986. There are 11 known rings, all very faint. There are 11 known rings, all very faint.
The material composing the rings is very The material composing the rings is very dark. dark.
The rings of Uranus were the first to be The rings of Uranus were the first to be discovered after those of Saturn. discovered after those of Saturn.
http://www.nmm.ac.uk/server/show/conMediaFile.6398
Uranus OccultationUranus Occultation
Satellites of UranusSatellites of Uranus
Uranus has 20 named satellites plus one Uranus has 20 named satellites plus one recently discovered which has yet to be recently discovered which has yet to be given a name. given a name.
The satellites are named after characters The satellites are named after characters from the writings of Shakespeare and from the writings of Shakespeare and Pope (Pope (Rape of the LockRape of the Lock))
Uranus’s Satellites (in order outward Uranus’s Satellites (in order outward from Uranus)from Uranus)
CordeliaCordelia PortiaPortia ArielAriel SycoraxSycorax
OpheliaOphelia RosalindRosalind UmbrielUmbriel ProsperoProspero
BiancaBianca BelindaBelinda TitaniaTitania SetebosSetebos
CressidaCressida 1986U101986U10 OberonOberon
DesdemonaDesdemona PuckPuck CalibanCaliban
JulietJuliet MirandaMiranda StephanoStephano
Uranus Family Portrait (IR)Uranus Family Portrait (IR)
MirandaMiranda
Voyager 2 revealed Miranda’s “mixed up” Voyager 2 revealed Miranda’s “mixed up” surfacesurface
Heavily cratered areas, with weird grooves, Heavily cratered areas, with weird grooves, valleys, and cliffsvalleys, and cliffs
Miranda may have been partially shattered and Miranda may have been partially shattered and reassembled reassembled
Consists of water ice and rock, about 440 miles Consists of water ice and rock, about 440 miles in diameter. in diameter.
Miranda is the daughter of the magician Miranda is the daughter of the magician Prospero in Shakespeare’s Prospero in Shakespeare’s The TempestThe Tempest
Miranda ViewsMiranda Views
http://www.solarviews.com/raw/uranus/miranda7.jpg
Cliffs of MirandaCliffs of Miranda
Groovy MirandaGroovy Miranda
Titania & ArielTitania & Ariel
Transit of UranusTransit of Uranus
The HST captured a view of Ariel crossing the disk of Uranus in July 2006
Lore of UranusLore of Uranus
HerschelHerschel: On March 13, 1781 William Herschel, while : On March 13, 1781 William Herschel, while observing the sky using a six-inch reflecting telescope, observing the sky using a six-inch reflecting telescope, discovered the planet Uranusdiscovered the planet Uranus
Odd appearance, it resembled a bluish disk. Odd appearance, it resembled a bluish disk. At first Herschel thought that he had discovered a new At first Herschel thought that he had discovered a new
comet. comet. Herschel observed the “comet” four days later and found Herschel observed the “comet” four days later and found
that it had moved slightly. that it had moved slightly. This confirmed that the discovery was something in the This confirmed that the discovery was something in the
solar system. solar system.
Herschel’s 6-inch ReflectorHerschel’s 6-inch Reflector
http://www.nasm.si.edu/ceps/etp/discovery/disc_planets.html
George’s StarGeorge’s Star In November 1781, the German astronomer In November 1781, the German astronomer
Johann Bode calculated the orbit of “Planet Johann Bode calculated the orbit of “Planet Herschel” and found that it lay twice as far from Herschel” and found that it lay twice as far from the sun as Saturnthe sun as Saturn
With one discovery, Herschel doubled the size With one discovery, Herschel doubled the size of the solar system.of the solar system.
Bode suggested the name Uranus because, in Bode suggested the name Uranus because, in mythology, Uranus was the father of Saturnmythology, Uranus was the father of Saturn
Herschel wanted to name it “Georgium Sidus” Herschel wanted to name it “Georgium Sidus” after the infamous George III of Englandafter the infamous George III of England
““Uranus” became the accepted name after 1850Uranus” became the accepted name after 1850
Neptune DataNeptune Data
Mean Distance from SunMean Distance from Sun2,792,400,000 miles 2,792,400,000 miles
28.8 AU28.8 AU
Diameter at the EquatorDiameter at the Equator30,770 miles 30,770 miles
Length of “Year” Length of “Year” (revolution (revolution around the sun)around the sun)
164.79 earth years 164.79 earth years
Diameter if Earth = 1Diameter if Earth = 13.89 3.89
Length of “Day”Length of “Day”16 hr. 3 min. 16 hr. 3 min.
Mass if Earth = 1Mass if Earth = 117.3 17.3
SymbolSymbol
Surface Gravity if Earth = 1Surface Gravity if Earth = 11.18 1.18
God of the SeaGod of the Sea
NeptuneNeptune: In Roman mythology Neptune : In Roman mythology Neptune (Greek Poseidon) was the god of the sea.(Greek Poseidon) was the god of the sea.
Neptune was discovered in 1846 at the Neptune was discovered in 1846 at the Berlin Observatory based upon a Berlin Observatory based upon a prediction by the French astronomer prediction by the French astronomer Leverrier.Leverrier.
This was the first time that a planet had This was the first time that a planet had been predicted to exist before its been predicted to exist before its discovery.discovery.
Twin of UranusTwin of Uranus
Neptune is composed of gas and is very Neptune is composed of gas and is very similar in size and composition to Uranus. similar in size and composition to Uranus.
Like Uranus, Neptune also has methane in Like Uranus, Neptune also has methane in its atmosphere, which gives the planet a its atmosphere, which gives the planet a blue color.blue color.
Magnetic FieldsMagnetic Fields
Uranus & Neptune:Uranus & Neptune: Magnetic fields are not centered on the planet’s Magnetic fields are not centered on the planet’s
corescores Both fields extremely tilted compared to the Both fields extremely tilted compared to the
rotation axesrotation axes Uranus, 59Uranus, 59ºº Neptune, 47Neptune, 47ºº Earth, 12Earth, 12ºº
With most other planets, the axes of rotation and With most other planets, the axes of rotation and magnetic field are fairly closemagnetic field are fairly close
The magnetic fields of Earth, Jupiter, and Saturn nearly align with their respective rotation axes.
In contrast, the magnetic and geographic poles of Uranus and Neptune differ greatly.
Voyager 2Voyager 2
SpacecraftSpacecraft: Neptune has been visited by : Neptune has been visited by only one spacecraft, Voyager 2 on August only one spacecraft, Voyager 2 on August 25, 1989. 25, 1989.
During its flyby, Voyager 2 discovered six During its flyby, Voyager 2 discovered six new satellites and observed the ring new satellites and observed the ring structure of Neptunestructure of Neptune
Voyager 2 had already visited Jupiter, Voyager 2 had already visited Jupiter, Saturn, and Uranus before encountering Saturn, and Uranus before encountering NeptuneNeptune
Voyager 2 ViewsVoyager 2 Views
Detail of Neptune’s clouds Neptune & Triton
Like Uranus, Neptune is Surrounded Like Uranus, Neptune is Surrounded by Thin, Dark Ringsby Thin, Dark Rings
Great Dark SpotGreat Dark Spot
Great Dark SpotGreat Dark Spot: For Voyager 2, displayed an : For Voyager 2, displayed an ever-changing atmosphere. Uranus was ever-changing atmosphere. Uranus was featurelessfeatureless
At the time of the Voyager 2 encounter, At the time of the Voyager 2 encounter, Neptune’s most prominent feature was the Great Neptune’s most prominent feature was the Great Dark SpotDark Spot
About half the size of Jupiter’s Great Red Spot About half the size of Jupiter’s Great Red Spot (about the same diameter as the earth)(about the same diameter as the earth)
Observations from the Hubble Space Telescope Observations from the Hubble Space Telescope in 1994 have revealed that the Great Dark Spot in 1994 have revealed that the Great Dark Spot has vanished! has vanished!
Neptune’s Great Dark SpotNeptune’s Great Dark Spot
Moon’s of NeptuneMoon’s of Neptune
Neptune has seven small moons and one large moon Neptune has seven small moons and one large moon named Triton.named Triton.
Neptune’s moons were named after “watery” characters Neptune’s moons were named after “watery” characters from Greek mythology.from Greek mythology.
Neptune’s’ Satellites (in order outward from Neptune)Neptune’s’ Satellites (in order outward from Neptune)
NaiadNaiad LarissaLarissa
ThalassaThalassa ProteusProteus
DespinaDespina TritonTriton
GalateaGalatea NereidNereid
TritonTriton
In Greek mythology, Triton is the son of In Greek mythology, Triton is the son of NeptuneNeptune
Triton revolution of Neptune is retrograde Triton revolution of Neptune is retrograde Triton may have formed elsewhere and Triton may have formed elsewhere and
was later captured by Neptunewas later captured by NeptuneTriton is about 25% water ice and 75% Triton is about 25% water ice and 75%
rockrockTriton is probably similar to PlutoTriton is probably similar to PlutoTriton is about 1,700 miles in diameterTriton is about 1,700 miles in diameter
Cantaloupe WorldCantaloupe World
Surface FeaturesSurface Features: Triton has a young : Triton has a young surface with few craters surface with few craters
Its southern hemisphere is covered with Its southern hemisphere is covered with an “ice cap” of frozen nitrogen and an “ice cap” of frozen nitrogen and methane. methane.
Complex ridges and valleys cover Triton’s Complex ridges and valleys cover Triton’s surface. surface.
In the Voyager 2 images, Triton’s surface In the Voyager 2 images, Triton’s surface resembles the skin of a cantaloupe. resembles the skin of a cantaloupe.
Triton (V2)Triton (V2)Triton
Ice VolcanoesIce Volcanoes
Voyager images of Triton reveal “ice volcanoes”Voyager images of Triton reveal “ice volcanoes” Eruptions of liquid nitrogen, dust, or methane Eruptions of liquid nitrogen, dust, or methane
compounds from beneath the surfacecompounds from beneath the surface Voyager images show an actual plume rising Voyager images show an actual plume rising
five miles above the surface and extending over five miles above the surface and extending over 90 miles “downwind” 90 miles “downwind”
Triton, Io, and Enceladus are the only other Triton, Io, and Enceladus are the only other bodies in the solar system besides earth that bodies in the solar system besides earth that display some form of volcanismdisplay some form of volcanism
Ice Ice Volcanoes Volcanoes
(V2)(V2)
•Dark streaks are possible “ice volcanoes”
Lore of NeptuneLore of Neptune
Galileo: In 1613, Galileo observed Galileo: In 1613, Galileo observed Neptune when it happened to be very near Neptune when it happened to be very near Jupiter, but he thought that it was only a Jupiter, but he thought that it was only a star. star.
If Galileo had been the discoverer of If Galileo had been the discoverer of Neptune, then the 8th planet would have Neptune, then the 8th planet would have been found before the 7th.been found before the 7th.
Leverrier & AdamsLeverrier & Adams
Adams & LeverrierAdams & Leverrier: Due to irregularities : Due to irregularities observed in the orbit of Uranus, the astronomers observed in the orbit of Uranus, the astronomers Adams and Leverrier predicted the existence Adams and Leverrier predicted the existence and location of a new planet beyond Uranus and location of a new planet beyond Uranus
This new planet was discovered by Galle and This new planet was discovered by Galle and d’Arrest on September 23, 1846. d’Arrest on September 23, 1846.
They pointed a telescope at the predicted They pointed a telescope at the predicted position and quickly located the new planet!position and quickly located the new planet!
Amazing use of Newton’s laws to find a new Amazing use of Newton’s laws to find a new planet!planet!