jef431e lec 1b

LECTURE – 1, continued: 

LECTURE – 1, continued PLANETS Inner Planets: Mercury, Venus, Earth, Mars Outer Planets: Jupiter, Saturn, Uranus, Neptune, Pluto

Thermal Histories of the Inner Planets:: 

Thermal Histories of the Inner Planets: The thermal history and resulting geologic activity of a planet are largely dependent on the planet’s size. Small bodies cool rapidly because they have large surface areas compared with their masses. Larger bodies retain heat longer and as a result, have prolonged periods of internal geologic activity, such as volcanism and crustal deformation (Hamblin and Christiansen, 1998).

Slide3: 

The Inner Planets (Terrestrial Planets: Mercury, Venus, Earth and Moon, Mars) Composition: silicates and metals (rocky materials) Density: 3.3-5.5 g/cm3 Velocity: high Mass: small Differentiation, geologic activity The Outer Planets (Jovian Planets: Jupiter, Saturn, Uranus, Neptune, Pluto) Composition: hydrogene, helium, methane, ammonia, water and ice Density: < 2 g/cm3 Velocity: low Mass: big No geologic activity (except Io, Europa, Ganymede, Enceladus, Miranda, Triton)

MERCURY: 

MERCURY Mercury is nearly 1.5 times larger in diameter than the Moon and has a much greater density. Its interior is made of dense iron metal. Mercury’s surface features indicate four major events (Hamblin and Christiansen, 1998): accretion, planetary differentiation and intense meteorite bombardment; formation of multiring basins; flooding of basins by the extrusion of basaltic lava; and light meteorite bombardment. Because there is no atmosphere or water on Mercury, its surface has not been modified by a hydrologic system.

Mercury and the Moon are strikingly similar. Each has a densely cratered terrain, multiring basins, younger seas of plains (maria) and yound rayed craters. The false color image on the left shows the surface is made of materials with different compositions, Courtesy of U.S Geological Survey and M.S Robinson (Hamblin and Christiansen, 1998, p 683): 

Mercury and the Moon are strikingly similar. Each has a densely cratered terrain, multiring basins, younger seas of plains (maria) and yound rayed craters. The false color image on the left shows the surface is made of materials with different compositions, Courtesy of U.S Geological Survey and M.S Robinson (Hamblin and Christiansen, 1998, p 683)

VENUS: 

VENUS Venus is most like Earth in both size and density. The surface of Venus is totally obscured by clouds of sulfuric acid in a thick atmosphere made up mostly carbon dioxide. Venus has a surface similar to the surface of Earth with continents and ocean basins. Venus has almost no water and because of an enhanced greenhouse effect in its carbon dioxide-rich atmosphere, surface temperatures (500oC) are higher than on Mercury. Its atmosphere exerts a pressure almost 90 times that of Earth’s. Its surface is young (500 million years old) and has been modified by tectonism and young extensive volcanism (80% of the planet). The surface of Venus has tectonic features (faults, fractures and uplifted domes). However, Venus has not developed a system of plate tectonics to recycle its lithosphere and rid its interior of heat. Venus, like Mars, seems to be loosing heat via hot spot development (Hamblin and Christiansen, 1998).

Topographic map of Venus shows that it consists mostly of low plains and several continent-sized highlands, including Ishtar Terra and Aphrodite Terra. Colors show elevation changes with purple lowest and red highest (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 689) : 

Topographic map of Venus shows that it consists mostly of low plains and several continent-sized highlands, including Ishtar Terra and Aphrodite Terra. Colors show elevation changes with purple lowest and red highest (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 689)

Impact craters on Venus are unique because of the high surface temperature and high atmospheric pressure. This crater is about 30 km in diameter. The asymmetrical, radial-lobate ejecta pattern suggests that the ejected material was fluid, like a mud flow. Note the bright flows extending to the upper right as part of the continuous ejecta deposit (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690): 

Impact craters on Venus are unique because of the high surface temperature and high atmospheric pressure. This crater is about 30 km in diameter. The asymmetrical, radial-lobate ejecta pattern suggests that the ejected material was fluid, like a mud flow. Note the bright flows extending to the upper right as part of the continuous ejecta deposit (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690)

Steep-sided, flat-topped domes similar to silicic domes on Earth. Their structure and morphology suggest that they were formed by viscous magma (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690) - Venus: 

Steep-sided, flat-topped domes similar to silicic domes on Earth. Their structure and morphology suggest that they were formed by viscous magma (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690) - Venus

A large structural dome cut by a complex fault system and flanked by a series of folds. The width of the image is about 125 km (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690) - Venus: 

A large structural dome cut by a complex fault system and flanked by a series of folds. The width of the image is about 125 km (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690) - Venus

Coronas are important volcano-tectonic features found on Venus. They may be underlain by mantle plumes (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690): 

Coronas are important volcano-tectonic features found on Venus. They may be underlain by mantle plumes (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 690)

EARTH: 

EARTH Major features of the continents: a basement complex (shield), which is composed of complexly deformed rocks eroded to near sea level; a stable platform, which is the area where the basement complex is covered with a veneer of horizonal rocks; a folded mountain belts. Oceanic crust differs strikingly from continental crust in rock types, structure, landforms, age and origin (Hamblin and Christiansen, 1998): The major features of the ocean floor are : the ocenaic ridge the abyssal floor, seamounts, trenches, continental margins.

Earth (Hesser and Leach, 1989): 

Earth (Hesser and Leach, 1989)

Orientale basin (1000 km in diameter) is a lunar impact structure. Concentric ridges were thrown up by complex rebounds in the moments after impact (Smith, 1981, p 446): 

Orientale basin (1000 km in diameter) is a lunar impact structure. Concentric ridges were thrown up by complex rebounds in the moments after impact (Smith, 1981, p 446)

The sinuous rilles are probably the results of collapsed lava tubes, similar to those oberved on large terrestrial basaltic volcanoes (Smith, 1981, p 446) – Apollo 15 : 

The sinuous rilles are probably the results of collapsed lava tubes, similar to those oberved on large terrestrial basaltic volcanoes (Smith, 1981, p 446) – Apollo 15

MARS: 

MARS There are many large and gigantic Earthlike surface features (rift valleys, volcanoes, dust storms, polar ice caps and dry river beds) on Mars. Its surface has been eroded by floods of water but presently, temperatures and atmospheric pressures are such that water can exist only as vapor or as ice. Now, wind is the major process altering its surface. Mars is much smaller than Earth, has less internal heat, cooled more quickly, and was geologicaly active over a much shorter period. An evidence for life (shaped like bacteria) in 1996 has been found in a meteorite thought to have come from Mars (Hamblin and Christiansen, 1998).

The planet Mars. Its surface is somewhat similar to the Moon’s, yet significant differences exist. Unlike the Moon, Mars has many features indicating that its surface has been modified by atmospheric processes, recent volcanic activity and crustal deformation (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 683) – Viking spacecraft : 

The planet Mars. Its surface is somewhat similar to the Moon’s, yet significant differences exist. Unlike the Moon, Mars has many features indicating that its surface has been modified by atmospheric processes, recent volcanic activity and crustal deformation (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 683) – Viking spacecraft

The Martian surface. The large boulder in the right foreground is approximately 2 m across. Many features show the importance of wind activity in the surface. The gravel surface probably formed as a lag deposit during wind deflation of the surface (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 684) – Viking spacecraft : 

The Martian surface. The large boulder in the right foreground is approximately 2 m across. Many features show the importance of wind activity in the surface. The gravel surface probably formed as a lag deposit during wind deflation of the surface (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 684) – Viking spacecraft

Volcanoes in the Tharsis region of Mars include huge structures, much larger than any found on Earth. Olympus Mons, the largest volcano on Mars, is shown here. It is 700 km across at the base and 23 km high. The complex caldera at the summit is 65 km in diameter (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 685) : 

Volcanoes in the Tharsis region of Mars include huge structures, much larger than any found on Earth. Olympus Mons, the largest volcano on Mars, is shown here. It is 700 km across at the base and 23 km high. The complex caldera at the summit is 65 km in diameter (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 685)

Dry stream channels on Mars are similar in many respects to dry riverbeds in arid region on Earth. Some have typical braided patterns; others meander. The drainage system is more than 500 km long (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 686) – Viking spacecraft: 

Dry stream channels on Mars are similar in many respects to dry riverbeds in arid region on Earth. Some have typical braided patterns; others meander. The drainage system is more than 500 km long (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 686) – Viking spacecraft

Landslides in Valles Marineris. The landslide on the far wall has two components : an upper blocky portion, which is probably disrupted cap rock, and a finely striated lobate extension, which is probably debris derived from the old cratered terrain exposed in the lower canyon walls. Similar lineations are found on terrestrial landslides and show direction of movement. This part of Valles Marineris is about 5 km deep. The image is approximately 200 km wide (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 687) : 

Landslides in Valles Marineris. The landslide on the far wall has two components : an upper blocky portion, which is probably disrupted cap rock, and a finely striated lobate extension, which is probably debris derived from the old cratered terrain exposed in the lower canyon walls. Similar lineations are found on terrestrial landslides and show direction of movement. This part of Valles Marineris is about 5 km deep. The image is approximately 200 km wide (Courtesy of U.S Geological Survey and M.S Robinson, Hamblin and Christiansen, 1998, p 687)

JUPITER: 

JUPITER Jupiter has a volume 1300 times greater than Earth’s. It has no solid surface and no record of a geologic history. Its density is 1.3 g/cm3. Jupiter and the rest of the large outer planets are composed dominantly of hydrogen and helium that cloak Earth-sized masses of silicates and metals. Jupiter’s moons : Io, Europe, Ganymede and Callisto (the Galilean satellites) They show a diverse landscape resulting from impact, volcanism and fracturing. Three of these moons have surfaces composed mostly of water ice. Io is composed of silicates and volcanically active. It is the most volcanically active in the solar system and probably has been throughout much of geologic time. Energy from tidal forces may give it contiunal energy boost. Europa and Ganymede as well as Jupiter exert a strong gravitational pull on Io forcing it into an eccentric orbit.

Slide23: 

Europe has a density 3 g/cm3 (dense silicate rock). It is surrounded by a frozen ocean of ice. Ganymede is the largest satellite of Jupiter. Its diameter is approximately 1.5 times that of Earth’s Moon. Its density is 1.9 g/cm3. It consists of 50% water ice surrounding a rocky core. Callisto is slightly smaller than the Ganymede. It consists of a rocky core surrounded by a thick mantle of ice. In contrast to the other Galilean Satellites, it is saturated with craters.

Jupiter (Courtesy of NASA, Hamblin and Christiansen, 1998, p 692) – Voyager 1: 

Jupiter (Courtesy of NASA, Hamblin and Christiansen, 1998, p 692) – Voyager 1

Moon of Jupiter: Io: A young surface formed by volcanism (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693): 

Moon of Jupiter: Io: A young surface formed by volcanism (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693)

Moon of Jupiter: Europa : A young surface of fractured ice (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693): 

Moon of Jupiter: Europa : A young surface of fractured ice (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693)

Moon of Jupiter: Ganymede: An older icy surface with complex history of crustal fragmentation. The inset shows the details of one area of grooved terrain (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693): 

Moon of Jupiter: Ganymede: An older icy surface with complex history of crustal fragmentation. The inset shows the details of one area of grooved terrain (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693)

Moon of Jupiter: Callisto: An ancient surface dominated by impact structures. (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693): 

Moon of Jupiter: Callisto: An ancient surface dominated by impact structures. (Courtesy of NASA, Hamblin and Christiansen, 1998, p 693)

The Great Red Spot, 20 000 km long and 10 000 km wide (Kaufmann and Comins, 1997, p 159): 

The Great Red Spot, 20 000 km long and 10 000 km wide (Kaufmann and Comins, 1997, p 159)

SATURN: 

SATURN Saturn is a gigantic ball of gas, mostly hydrogen and helium. It has 18 satellites. Saturn’s rings extend over 40 000 km and are only a few kiometers thick. The rings are probably made up of billions of particles of ice and ice-covered rock, ranging from a few micrometers to a meter or more in diameter. Except for Titan, the seven largest moons of Saturn are small icy bodies. Many of the moons have large fracture systems, other surface markings resulting from icy volcanism.

Saturn and its major moons: Dione, Tethys, Mimas, Enceladus, Rhea and Titan (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager: 

Saturn and its major moons: Dione, Tethys, Mimas, Enceladus, Rhea and Titan (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager

Numerous thin ringlets comprising Saturn’s rings. The rings are actually composed of thousands of closely spaced ringlets (Kaufmann and Comins, 1997, p 170) – Voyager 2: 

Numerous thin ringlets comprising Saturn’s rings. The rings are actually composed of thousands of closely spaced ringlets (Kaufmann and Comins, 1997, p 170) – Voyager 2

URANUS: 

URANUS Uranus has no solid surface but it is enveloped by a thick atmosphere hydrogen an helium. Its cloud layer is bland and bluish because of the presence of methane. Uranus has five major moons (Umbriel, Ariel, Miranda, Titania and Oberon). Their surfaces are nearly saturated with craters.

Uranus and its five major satellites: Umbriel, Ariel, Oberon, Miranda and Titania (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager: 

Uranus and its five major satellites: Umbriel, Ariel, Oberon, Miranda and Titania (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager

NEPTUNE: 

NEPTUNE Neptune is only slightly smaller than Uranus and is similar to its neighbor in composition. Both planets are called as twins of the outer solar system. They have large cores of water ice and rock surrounded by thick atmosperes of hydrogen, helium and minor methane. Neptune has a system of rings made of ice particles in orbit around the planet. There are two moons. Its largest satellite is Triton which has large variety of geologic features including ice caps, fractured terrain, lava lakes and volcanic or geyser eruptions.

Neptune and its largest satellite, Triton. Neptune is a giant gaseous planet with a banded blue atmosphere decorated with brilliant white clouds of methane ice (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager: 

Neptune and its largest satellite, Triton. Neptune is a giant gaseous planet with a banded blue atmosphere decorated with brilliant white clouds of methane ice (Courtesy of NASA, Hamblin and Christiansen, 1998, p 696) - Voyager

PLUTO: 

PLUTO Pluto is the farthest, the smallest, the coldest and the darkest. It takes 250 years to complete one orbit. It lacks a thick, hydrogene rich atmosphere. It has one moon (Charon). Pluto’s surface is dominated by nitrogen ice.

Pluto is the most distant planet in the solar system. Pluto and its moon, Charon (Courtesy of Hubble Space Telescope Team, Hamblin and Christiansen, 1998, p 696) - : 

Pluto is the most distant planet in the solar system. Pluto and its moon, Charon (Courtesy of Hubble Space Telescope Team, Hamblin and Christiansen, 1998, p 696) -