Unformatted text preview: The Planets The Development of Solar System Model Model Ptolemy Ptolemy – Geocentric (earth-centered) model model Nicolaus Copernicus – Heliocentric (suncentered) model of the solar system Johannes Kepler – Proposed the laws of Johannes planetary motion. Supported the heliocentric model of solar system heliocentric Galileo Galileo Galilei – Made astronomical discoveries with the aid of the telescope discoveries His views supported the heliocentric His model. model. Galilieo’s discoveries Galilieo’s Discovered four satellites orbiting Jupiter Discovered that planets are circular disk, Discovered not just points of light not Discovered that Venus has phases, just as Discovered the moon does the Discovered that the moon has craters Discovered that the sun has sunspots Two categories of planets Two Terrestial (Earth-like) Jovian (Jupiter-like) Terrestial Planets Terrestial Mercury, Venus, Earth, Mars Resemble Earth in appearance Much smaller than the Jovian planets Jovian Planets Jovian Jupiter, Saturn, Uranus, Neptune Large planets, consists of gaseous Large atmospheres of hydrogen, helium, ammonia, and methane ammonia, Composition of the Planets Composition Terrestial: Terrestial: Dense, mostly rocky, small amounts of ice. High densities. amounts Jovian: Contain large amounts of gases Jovian: (methane, ammonia, hydrogen, and helium). Low densities helium). Atmospheres of the Planets Atmospheres Terrestial: Terrestial: Meager atmospheres Jovian: Very thick atmospheres of Jovian: hydrogen, helium, methane, and ammonia hydrogen, Mercury Mercury Closest planet to the sun Has no atmosphere Heavily cratered Period of Rotation: 59 days Period of Revolution: 88 days Has greatest temp extremes: highest Has temp. = 800oF lowest temp. -290oF temp. Mercury (cont.) Mercury Days Days and nights on Mercury about 3 months months Has no known satellites (moons) Venus Venus Very Very similar to earth in terms of size, density, mass density, Has heavy cloud cover Clouds consists of carbon dioxide Atmosphere is 97% carbon dioxide Pressure is about 90 times that of earth Clouds produce droplets of sulfuric acid Venus (cont.) Venus Surface temperature: 900oF Greenhouse effect Mars Mars Atmosphere Atmosphere consists of carbon dioxide and trace amounts of water vapor and Atmosphere is thinner than earth Mars has polar ice caps. Mars has occasional dust storms Mars Mars has th...
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- Fall '10
- Solar System, atmosphere atmosphere