D. A system of assumptions and principles applicable to a wide range of phenomena that has been repeatedly verified

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1 ASTRONOMY 1 EXAM 1 Name Identify Terms - Matching 1 point each = 20 pts.) 1 Solar System G 7. aphelion N 14. eccentricity M 2. Planet E 8. apparent visual magnitude R 15. empirical Q 3. Star P 9. ecliptic F 16. heliocentric universe B 4. Astronomical unit J 10. flux O 17. inverse square relation T 5. Light-year C 11. revolution L 18. mass I 6. Milky way Galaxy K 12. rotation S 19. theory D 13. scientific model H 20. weight A A. The force on the object due to gravity B. the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. C. Unit of distance equal to the distance light travels in a year D. A system of assumptions and principles applicable to a wide range of phenomena that has been repeatedly verified E. A nonluminous body in orbit around a star, large enough to be spherical and to have cleared its orbital zone of other objects F. The apparent path of the sun around the sky G. The sun and planets, asteroids, comets and so on. H. A scientific metaphor; a concept that organizes thought about an aspect of nature without necessarily being literally true. I. Measure of the amount of matter making up an object J. Average distance from the Earth to the sun K. The spiral Galaxy containing our sun, visible in the night sky as the Milky Way L. Orbital motion about a point located outside the orbiting body M. A number between 1 and 0 that describes the shape of an ellipse N. the point in the orbit of a planet, asteroid, or comet at which it is furthest from the sun. O. A measure of the flow of energy through a surface. Usually applied to light P. A globe of gas held together by its own gravity and supported by the internal pressure of its hot gases, which generate by nuclear fusion. Q. based on, concerned with, or verifiable by observation or experience rather than theory or pure logic R. A measure of the brightness of a star as seen by human eyes on Earth S. Motion around an axis passing through the rotating body T. The principle in physics that the effect of certain forces on an object varies by the inverse square of the distance between the object and the source of the force.

2 Multiple Choice (2 pts each) 1. The diagram below represents Earth at four different positions, A, B, C, and D, in its orbit around the Sun. At which location is the northern hemisphere experiencing summer? 2. What is represented by the diagram below? a) changing phases of the Sun b) changing phases of the Sun c) stages in an eclipse of the moon d) stages in an eclipse of the sun 3. Which diagram correctly shows the direction of Earth s rotation and revolution?

3 4. The symbols below are used to represent different regions of space Which diagram shows the correct relationship between these four regions? [If one symbol is within another symbol, that means it is a part of, or included in that symbol] 5. The diagram below represents a simple geocentric model. Which object is represented by the letter X? a. Earth b. Sun c. Moon d. Polaris 6. Kepler's second law implies that A. planet should move at its greatest speed when it is closest to the sun. B. the most massive planets will have the greatest speed in their orbits C. the speed of a planet in its orbit depends on the size of the epicycle D. the mass of the planet determines how far the planet is from the sun 7. Difference between mass and weight is a. mass is a force and weight is a quantity b. mass and weight both are force c. mass and weight both are quantities d. mass is quantity and weight is force 8. The Sun's position in space is best described as the approximate center of a. A constellation b. The milky way galaxy c. Our solar system d. The universe 9. It s difficult to detect planets around a star other than our Sun because a. they only orbit perpendicular to our line of sight, so they don t reflect any light, and we can t see them b. they are much too small, too faint, and too close to the glare of their star to be visible directly c. There are no planets around other stars.

4 10. Newton concluded that some force had to act on the moon because a. a force is needed to keep the moon in motion. b. a force is needed to pull the moon outward. c. a force is needed to pull the moon away from straight-line motion. d. the moon moved at a constant velocity 11. In each diagram below, the mass of the star is the same. In which diagram is the force of gravity greatest between the star and the planet shown? 12. An amateur astronomer testing a new camera happens to catch a supernova as it's being born. The supernova is 80 million light-years away. The supernova actually happened a. 3 days ago, when the astronomer saw it. b. There s no way to know. c. 80 years ago d. 80 million years ago 13. The seasons of the Earth result from a) the tilt of the Earth's rotation axis a) the Earth being farther from the Sun in winter because of its b) elliptical orbit c) the varying speed of the Earth in its orbit d) the precession of the Earth's rotation axis 14. The scientist who formulated the three laws of planetary motion by analyzing the data on the precise location of planets in the sky was: a. Tycho Brahe b. Galileo Galilei c. Johannes Kepler d. D. J. C. Adams 15. Currently the Earth s Northerly axis of rotation points at our North Star, Polaris. In another 14,000 years it will point at Vega. This is due to a) Precession b) Elliptical motion c) Retrograde motion d) Deferential motion

5 16. The force due to gravity between two objects depends on I. The mass of each object II. The distance each object is from Earth III. The distance between the two objects. IV. The speed of light A. I & II B. I & III C. II & IV D. I, II & III 17. In what fundamental way did the work of Galileo differ from his predecessors in how he thought about the sky? a. Galileo consulted many authorities before coming to scientific conclusions, instead of working on his own b. Galileo translated the works of the ancient Greek astronomers, and relied on their wonderful abilities to think through difficult problems c. Galileo used instruments and experiments to show him what nature was doing, instead of relying on pure logic d. Galileo believed that the Earth was the center of the solar system, and everything revolved around it 18. The current world population is about 7.6 billion people (7.6 x 10⁹ ) Or a b c d The sun is a. A star which generates its own energy b. 1 AU from Earth c. Visible by its own light emission d. All of the above 20. The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called? a. Zodiacs b. Constellations c. Asterisms d. Epicycles 21. When it comes to our place in the solar system today, which model do we accept? a. geocentric b. heliocentric c. Ptolemaic d. Aristotelean 22. Why does the Sun rise and set? a. The shape of Earth s orbital path around the Sun causes the Sun to rise and set. b. The Moon blocks out the Sun for roughly twelve hours a day, causing Earth to experience night time. c. The Moon s gravitational pull forces Earth to face away from the Sun for about twelve hours a day. d. Earth spins on its axis, making one full rotation in about 24 hours.

6 23. Here is a table showing visible passes of the Hubble Space telescope today and the next few days It is brightest e) Today, Feb 27 b) Feb 28 c) March 1 d) March Which of the following statements about the celestial sphere is NOT true? a. The "celestial sphere" is just another name for our universe. b. The Earth is placed at the center of the celestial sphere c. The celestial sphere does not exist physically 25. The average distance from Earth to the sun is a. 1 ly b. 1 million km c. 1 million miles d. 1 billion km e. 1 astronomical unit

7 Write a brief essay on 3 of the following 4 topics 1.What is the difference between our solar system and our galaxy? Between our galaxy and the universe? To get full credit mention Solar system - The sun and planets, asteroids, comets and so on Galaxy - A large system of stars, star clusters, gas, dust, and nebula orbiting a common center of mass Universe - all existing matter and space considered as a whole The solar system is part of the galaxy which is part of the universe 2. In what way did the astronomical observations of Galileo support a heliocentric cosmology? List at least two observations. Some of the observations to list: Moons orbiting Jupiter Phases of Venus Sunspots Mountains, valleys on Moon 3.What would our seasons be like if Earth were tipped 45 o instead of 23.5 o? What would they be like if Earth s axis were perpendicular to its orbit? What would our seasons be like if Earth were tipped 45 o : The seasons would be more pronounced, i.e. the summers would be hotter, and the winters colder. If Earths axis of rotation were perpendicular to the plane of its orbit the seasons on Earth would not vary. It would be one continuous season. The tilt of our planet gives us seasons, no tilt means no season change. 4. How do a hypothesis, a theory, and a law differ? Hypothesis A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation A scientific theory - a well- substantiated explanation of an aspect of the natural world that is acquired through the scientific method, and repeatedly confirmed through observation and experimentation A law is a mathematical relationship that is consistently found to be true.