The Solar System Chapter 29 Review

Main Concepts and Big Ideas The Heliocentric Model and Geocentric Model were ways 3 Dead Greek Guys thought the planets move in the Solar System Terrestrial and Jovian Planets are the two major types of planets in the Solar System

Geocentric Model Definition: Author: Aristotle All planets and Sun revolve around the Earth - Earth is at center of Solar System Author: Aristotle Problem: Geocentric Model does not explain Retrograde Motion Earth SUN Mars

Next Dead Guy: Ptolemy Aristotle’s Geocentric Model could not explain why a planet could have both a forward and reverse motion in the sky – Retrograde Motion Ptolemy explained Retrograde Motion through Epicycles Earth SUN Mars Epicycle

Epicycles & Retrograde Motion Orbital Path Mars Retrograde Motion

Heliocentric Model Definition: Author: All Planets revolve around Sun Author: Copernicus Confirmation of Heliocentric Model by Galileo through observations made with newly invented telescope

The Terrestrial Planets The terrestrial planets are the four innermost planets in the solar system, Mercury, Venus, Earth and Mars. They are called terrestrial because they have a compact, rocky surface like the Earth's. The planets, Venus, Earth, and Mars have significant atmospheres while Mercury has almost none.

The Inner Planets Mercury Large number of craters suggest little change since formation Thin Atmosphere Closeness to Sun Small Size Venus Very slow rotation on axis – every 243 days Orbital period of 224 High Volcanic Activity Very Hot!! Close to sun & insulating atmosphere

The Inner Planets Mars & Earth Common Events Earth Volcanism Presence of Water Atmosphere Earth Escape of insulating Carbon Dioxide keeps Earth from getting too hot

The Jovian Planets Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets, because they are all gigantic compared with Earth, and they have a gaseous nature like Jupiter's. The Jovian planets are also referred to as the gas giants, although some or all of them might have small solid cores.

The Outer Planets Jupiter Saturn Uranus 92% of Jupiter is Hydrogen & Helium – similar composition to Sun Saturn Least dense in Solar System Period: 29.5 Years Ring System Uranus Horizontal Axis – only planet that rotates this way

The Sun n/a Mercury 5,791,000 1.9 Venus 108,200,000 .39 A.U. 3.5 Celestial Body Distance from sun (km) Distance From Sun (AU) Comparative Distance (Feet) The Sun n/a   Mercury 5,791,000  1.9 Venus 108,200,000 .39 A.U.  3.5 The Earth 149,600,000 1 A.U. 4.5 Mars 227,940,000 1.5 A.U  7.5 Jupiter 778,330,000 6.2 A.U.  25.5 Saturn 1,429,400,000 9.5 A.U.  46.5 Uranus 2,870,990,000 19.2 A.U.  94.1 Neptune 4,504,000,000 30.1 A.U.  147.6

Asteroids, Comets, and Meteoroids Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets. Asteroids are material left over from the formation of the solar system. One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago.

Asteroids Asteroids – or Minor Planets – are fragments of rock that orbit the Sun Most asteroids exist in a region between the orbits of Mars and Jupiter – The Asteroid Belt Classified based on composition Asteroids are remains of planetesimals – affected by Jupiter Two types of asteroids NOT in Asteroid Belt between Mars and Jupiter – Trojan Asteroids & Earth Grazers

Comets Made of dust and ice Originate in Oort Clouds Orbit Sun in large elliptical orbits Coma and tail – SOLAR WIND

Meteoroids, Meteors and Meteorites Meteoroids are small bits of rock or metal flying through space Visible fireballs come from meteors burning up in atmosphere Any part that hits the Earth is called a meteorite

Review Questions Directions: At the bottom of your sheet of notes, answer the following questions: Between the orbits of what planets is the asteroid belt located? In what direction does the tail of the comet go? How is a meteoroid different from a meteorite? In what way are the orbits of Trojan asteroids and Earth Grazers unlike orbits of other asteroids?