Ch. 22 Origin of Modern Astronomy Pretest

Transcription

1 Ch. 22 Origin of Modern Astronomy Pretest

2 Ch. 22 Origin of Modern Astronomy Pretest 1. True or False: Early Greek astronomers (600 B.C. A.D. 150) used telescopes to observe the stars.

3 Ch. 22 Origin of Modern Astronomy Pretest 2. What lies at the center of our solar system? a. the sun b. Mars c. Earth d. the moon

4 Ch. 22 Origin of Modern Astronomy Pretest 3. What is rotation?

5 Ch. 22 Origin of Modern Astronomy Pretest 4. What is the approximate time that it takes Earth to rotate on its axis? a. 12 hours b. 24 hours c. 30 days d. 365 days

6 Ch. 22 Origin of Modern Astronomy Pretest 5. What was the most important accomplishment of the Apollo moon missions?

7 Ch. 22 Origin of Modern Astronomy Pretest 6. Approximately how long does it take for the moon to go through all of its phases? a. 12 hours b. 24 hours c. 30 days d. 365 days

8 22.1 Early Astronomy You will be able to Describe the contributions of ancient Greeks to astronomy. Compare and Contrast the geocentric and heliocentric models of the solar system

9 22.1 What is Astronomy Astronomy is the science that studies the universe. It includes the observation and interpretation of celestial bodies and phenomena.

10 Astrolabe Astrolabes are used to show how the sky looks at a specific place at a given time. iphone App: Astrock, the Astronomical Clock 1.0

11 22.1 Geocentric vs. Heliocentric

12 22.1 Geocentric vs. Heliocentric Geocentric Model Geo (Latin and Greek prefix) = Earth Centric (is from the Greek word kentrikos) = located in the center Geocentric means having Earth as the center. In the ancient Greeks geocentric model, the moon, sun, and the known planets Mercury, Venus, Mars, and Jupiter orbit Earth.

13 With the naked eye, one can see five planets: Mercury, Venus, Mars, Jupiter, and Saturn. In the photo at the right, you can see (from top to bottom) Saturn, Venus, Jupiter, and Mercury in alignment with the recently set Sun.

14 22.1 Geocentric vs. Heliocentric Heliocentric Model Helio (is a Latin and Greek prefix) = Sun In the heliocentric model, Earth and the other planets orbit the sun.

15 22.1 Ancient Greeks 1) Aristotle Greek ( B.C.) He concluded that the earth was round because it always casts a curved shadow on the moon.

16 22.1 Ancient Greeks 2) Ptolemy Ptolemy created a model of the universe that accounted for the movement of the planets. (geocentric model) Retrograde motion is the apparent westward motion of the planets with respect to the stars.

17 Retrograde Motion

18 Retrograde Motion The image below displays the actual retrograde motion of Jupiter (brighter) and Saturn (dimmer) over eleven months:

19 22.1 The Birth of Modern Astronomy 3) Nicolaus Copernicus Copernicus concluded that Earth is a planet. He proposed a model of the solar system with the sun at the center. (Heliocentric model)

20 22.1 The Birth of Modern Astronomy 4) Johannes Kepler (1 of 2) Kepler discovered three laws of planetary motion: 1. Orbits of the planets are elliptical. 2. Planets revolve around the sun at varying speed. 3. There is a proportional relationship between a planet s orbital period and its distance to the sun.

21 22.1 The Birth of Modern Astronomy 4) Johannes Kepler (2 of 2) An astronomical unit (AU) is the average distance between Earth and the sun; it is about 150 million kilometers.

22 Planet Revolution

23 22.1 The Birth of Modern Astronomy 5) Galileo Galilei Galileo s most important contributions were his descriptions of the behavior of moving objects. He developed his own telescope and made important discoveries: 1. Four satellites, or moons, orbit Jupiter. 2. Planets are circular disks, not just points of light. 3. Venus has phases just like the moon. 4. The moon s surface is not smooth. 5. The sun has sunspots, or dark regions.

24 22.1 The Birth of Modern Astronomy 6) Sir Isaac Newton Newton was the first to formulate and test the law of universal gravitation. Universal Gravitation Gravitational force decreases with distance. The greater the mass of an object, the greater is its gravitational force. If the airplane weighs pounds on the surface of the earth, it weighs 9965 pounds at feet.

25 Gravity s Influence on Orbits

26 22.1 Early Astronomy You will be able to Describe the contributions of ancient Greeks to astronomy. Compare and Contrast the geocentric and heliocentric models of the solar system