Europa Phoenician from to Io stay abducted Callistoaanoble nymph of Artemisdescended
(Diana) vowed a by Zeusbut in the form of whitedisguised
bull and taken to Crete virgin, seduced byaZeus as Artemis and
transformed into a bear almost slain by her son, Arcas, but placed among the stars to become a constellation Ganymede Trojan the most attractive of mortals
Io Priestess of Heraprince, seduced by Zeus abducted by Zeus to serve as cup bearer to the Gods
Orbits of the Galilean Satellites Radius (RJ): Period (days): Io 5.9 1 Europa 9.4
2 Ganymede 15 4 Callisto 26.3 9.43 Question
What is the relationship between the orbital periods of the four Galilean satellites of Jupiter? A. 1:2:4:8 Europa orbits Jupiter twice, Ganymede orbits four times and Callisto orbits eight times during one Io orbit.
B. 1:2Europa takes twice as long to orbit Jupiter as Io, but there is no integer relationship between Callisto and Ganymede with the inner two Galilean moons. C. 1:2:4Io orbits Jupiter four times and Europa orbits twice during one Ganymede orbit, but there is no integer relationship between Callisto and any of the other Galilean moons.
D. 1:1:1:1They all orbit with the same period. E. The periods appear to be random, with no simple relationship between them. Relative Sizes and Distances from Jupiter Voyager 1February 1979
Formation of Galilean Satellites Protosun ice-limit Proto-Jupiter ice limit Formation of Galilean Satellites
Io Anomaly Discovery Voyager 1 March 8,1979 Whats this? an unknown moon behind Io???
No! A volcanic plume from Pele Voyager Mosaic Image Except for these areasnot seen by Voyager Galileo Spacecraft 1996
Galileo composite Image1996 Side of Io facing Jupiter GalileoNovember 1997
Tvashtar PlumeNew Horizons, Feb 28, 2007 Lava Flow from Tvashtar 2000 Change in Lava Flow from Tvashtar 1999-2000
Eruption from Pillan Patera after several months Infrared Glow from Active Volcanoes Question
The source of intense heating in the interior of Jupiter's moon Io, causing continuous and intense volcanic activity, is ______. A. tidal flexing and distortion, caused by Jupiter and the other large moons. B. frictional heating as the solar wind impacts the moons surface.
C. a black hole in its core swallowing up the matter around it causing Io to slowly contract and heat up. D. heat released as it continues to shrink following its formation, converting gravitational potential energy into heat. E. Radioactive decay of its large deposits of
uranium Ejection of Sulfur from Ios Volcanoes Earth-based Infrared Image Io Torus
5 Million Amps of Current flows between Jupiter and Io! Interior of Io Thin crust of sulfur and SO2 Thicker crust and Mantle of Silicates
Dense metallic core EuropaGalileo Image 1996 Galileo Sept 19, 2003False Color Infrared and Visible Europa exhibits a
secondary magnetic field Induced by the Jupiters magnetic field moving through it as Jupiter rotates.
Strong evidence that Europa has a subsurface, conductive liquid ocean. Europas Ridges and Jumbled Terrain
Triple Bands Formed when crust fractures Ridges separate and darken Water oozes up and freezes when another fracture occurs A section of a triple band crosses the upper left of
the picture and extends for hundreds of miles across the surface. Triple bands derive their name from their appearance at lower resolution as a narrow bright band flanked by a pair of darker bands. At the high resolution seen here, the triple band is more complex and is composed of a system of
ridges 6 kilometers across. Some ridges about 180 meters high. Other features include a hill in the center of the picture about 480 meters high. Two mounds about 6 kilometers across are seen in the bottom of the picture. The ridges, hills and mounds probably represent
uplifts of the icy crust of Europa by processes originating from the interior. Ice Rafts on Europa Interior of Europa
Question The weak and variable magnetic field on Europa measured by the Galileo spacecraft is generated by ______. A. Thousands of electric motors still running after Europas civilization went extinct B. electrical currents flowing between Europa and Jupiter
C. the motion of molten iron in Europa's core D. electrical currents in the liquid metallic hydrogen in Europas core E. electrical currents in Europas subsurface ocean water, induced by Jupiter's intense rotating magnetic field
GanymedeSide Facing Away from Jupiter Galileo Regio Grooved Terrain on Ganymede Plate Tectonics on Ganymede?
Interior of Ganymede Ice Crust Icy Mantle probably includes water and slush zone Large mantle of
silicates Iron core CallistoGalileo, May 2001 Only complete global color image taken by Galileo
Valhalla Basin Largest multiringed impact in solar system Lack of craters <1 km Covered with dark, dusty
material Interior of Callisto Thick Ice Crust Water below crust? Mantle of rock and ice
Question The surfaces of Ganymede and Callisto appear to consist mostly of ______. A.an organic polymer-like goo B.Ice C.rocks and lava
D.frozen hydrogen and helium E.Hot magma rich in sulfur compounds It's like imagining we'd flown into the solar system the day before and said let's explain it in ten minutes. There was Callisto, with the highest density of craters of any Galilean satellite, the oldest of
the Galilean surfaces, featuring a huge bull's eye that is the largest single contiguous feature seen so far in the solar system. There was Ganymede, cratered, but also overrun with fault lines that looked like tire tracks in the desert, showing a surface that had laterally slid, faulted and sheared and sheared again, twisted and torn apart. There was Iothe most bizarrethe one that scientists thought would be most lunarlike, showing a surface that had apparently been cooked, steamed and fumed out leaving
deposits all over the surface like you might see around a fumarole at Yellowstone. It makes it likely that Io is still volcanically active. There was Europa, with huge linear features unlike those of the other three GalileansEuropa the mystery satellite, waiting for the probing eyes of Voyager 2 to survey it in early July. Ed Stone summed it all up, "I think we have had almost a decade's worth of discovery in this two-week period ."
Key Ideas
Nature of the Galilean Satellites: The four Galilean satellites orbit Jupiter in the plane of its equator all in
synchronous rotation. The orbital periods of Io, Europa, and Ganymede are in the ratio 1:2:4. The two innermost Galilean satellites, Io and Europa, have roughly the same size and density as our Moon. They are composed principally of rocky material. The two outermost Galilean satellites, Ganymede and
Callisto, are roughly the size of Mercury. Lower in density than either the Moon or Mercury, they are made of roughly equal parts ice and rock. The Galilean satellites probably formed in a similar fashion to our solar system but on a smaller scale. Key Ideas
Io: Io is covered with a colorful layer of sulfur
compounds deposited by frequent explosive eruptions from volcanic vents. These eruptions resemble terrestrial geysers. The energy to heat Ios interior and produce the satellites volcanic activity comes from tidal forces that flex the satellite. This tidal flexing is aided by the 1:2:4 ratio of orbital periods among the inner three Galilean
satellites. The Io torus is a ring of electrically charged particles circling Jupiter at the distance of Ios orbit. Interactions between this ring and Jupiters magnetic field produce strong radio emissions. Io may also have a magnetic field of its own.
Key Ideas Europa: While composed primarily of rock, Europa is covered with a smooth layer of water ice. The surface has hardly any craters, indicating a geologically active history. Other indications
are a worldwide network of long cracks and ice rafts that indicate a subsurface layer of liquid water or soft ice. As for Io, tidal heating is responsible for Europas internal heat. An ocean probably lies beneath Europas frozen surface. Minerals dissolved in this ocean may explain Europas induced magnetic field.
Key Ideas Ganymede: Two types of terrain are found on the icy surface of Ganymede: areas of dark, ancient, heavily cratered surface and regions of
heavily grooved, lighter-colored, younger terrain. Ganymede is highly differentiated, and probably has a metallic core. It has a surprisingly strong magnetic field and a magnetosphere of its own. While there is at present little tidal heating of Ganymede, it may have been heated in this fashion in the past. An induced magnetic field
suggests that it, too, has a layer of liquid water beneath the surface. Key Ideas Callisto: Callisto has a heavily cratered crust of
water ice. The surface shows little sign of geologic activity, because there was never any significant tidal heating of Callisto. However, some unknown processes have erased the smallest craters and blanketed the surface with a dark, dusty substance. Magnetic field data seem to suggest that
Callisto has a shallow subsurface ocean. Key Ideas Other Satellites: As of 2006, Jupiter has a total of 63 known satellites.
In addition to the Galilean satellites, Jupiter has four small inner satellites that lie inside Ios orbit. Like the Galilean satellites, these orbit in the plane of Jupiters equator. The remaining satellites are small and move in much larger orbits that are noticeably inclined to the plane of Jupiters equator. Many of these
orbit in the direction opposite to Jupiters rotation.
