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Published byGeorgina Cannon Modified over 8 years ago
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ORIGINS Oceans & Continents Crust Earth Solar System Universe
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The Universe Planets Stars Galaxies Clouds of Dust & Gas Interstellar Space
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Clouds of dust and gas in Eagle Nebula (Hubble Picture )
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View of Galaxies in deep space from Hubble space telescope
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Sombrero Galaxy
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Andromeda Galaxy
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Milky Way Galaxy
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Scientific Method Observations or experiments Hypotheses Testing Theories (Scientific Truths)
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Origin of Universe Evidence All galaxies in universe appear to be moving away from one another (Red Shift in Starlight) The greater their distance the faster they are receding The temperature of interstellar space is not 0 o K but 2.7 o K Big Bang Theory
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Origin of Solar System Evidence Astronomical observations of stars beyond solar system Observations of structure & composition of solar system Internal structure and composition of Earth
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Star Formation in a Dust and Gas Cloud in Scorpius
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Sun during eclipse
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Solar Spectrum
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The Sun Sun makes up 99.9% of Solar System Sun is mainly made of: Hydrogen (element #1, simplest and most abundant element in universe) Helium (element #2, second most abundant) Solar energy produced by nuclear fusion 4 Hydrogen nuclei = 2 Helium nuclei + energy
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The Solar System With exception of Pluto, all planets occupy sub-circular orbits All orbit in the same plane (ecliptic) and in same direction Nearly all rotate in same direction about axes that are nearly perpendicular to ecliptic
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The Planets Inner Planets Mercury, Venus, Earth, Mars Small, dense, rocky. Few moons Outer Planets Jupiter, Saturn, Uranus, Neptune Large, low density, icy. Many moons Pluto
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Solar System and Outer Planets
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Internal structure of Earth Atmosphere <1 g/cm 3 Hydrosphere 1 g/cm 3 Crust 2.7-2.9 g/cm 3 Mantle 3.3-5.6 g/cm 3 Core 10-14 g/cm 3 A Differentiated Planet
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Nebular Theory Star systems are formed by the gravitational collapse of diffuse clouds of dust and gas (nebulae) Cold clouds of dust and gas (mainly hydrogen) are most abundant constituents of universe Gravitational collapse always leads to rising temperatures.
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Planet Earth Rising temperatures lead to partial melting Light melting fractions rise Heavy melting fractions sink Result - a layered structure with core, mantle, crust, ocean and atmosphere
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Crust– Two Types BASALTIC CRUST 2.9 g/cm 3 (3-5mls thick) Iron, magnesium, silica rock (mafic rock) GRANITIC CRUST 2.7 g/cm 3 (10-40mls thick) Aluminum, silica rock (felsic rock) Crust rigid and brittle generates earthquakes
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Isostacy The floating balance that exists between dense plastic mantle and light brittle crust
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Elevation of Earth’s Surface Composition Density Temperature Thickness
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