Test 1 Review

Test Date: 10/22/2021

Old exams (multiple choice question examples): old multiple choice exam dealing with naked eye astronomy, and Last year's final (pdf file) (roughly 30-35% of the questions are relevant dealing with naked eye astronomy, development of modern astronomy, and basic features of the Solar System).

Sample short answer questions to aid in your study.

0. Astronomy, as a field, developed because of its ability to offer atable clocks to keep track of time. What are the various motions and their associated periods that give rise to timekeeping on the Earth? What is meant by sidereal? What is meant by synodic?
1. What is the Celestial Sphere? What are equinoxes? What are Solstices? What is the difference between Vernal Equinox and Autumnal Equinox? How are the equinoxes and solstices defined? What is the ecliptic? How is it defined? What is the ecliptic plane? Roughly, where is the Sun on December 22? March 21? How are the North (South) Celestial Pole related to the North (South) Pole(s) of the Earth? What is the Celestial Equator? The Celestial Sphere is not a physical model. What does this statement mean? What arguments and evidence did the ancient Greeks use to justify the Celestial Sphere model. Sketch a Celestial Sphere and mark the NCP, the SCP, the Celestial Equator, the Ecliptic, and the locations of the solstices and equinoxes.
2. What is the Horizon system? What (and where) is the horizon? What is the nadir? What is the zenith? What and where is the Celestial Meridian in the horizon system?
3. In which direction does the Earth spin as viewed from the NCP? What is the altitude of the North Celestial Pole for a given observer on the Earth? What is the angle the Celestial Equator makes with the horizon for a given observer on the Earth?
4. Sketch the horizon system for an observer in Eugene, OR marking the zenith, nadir, horizon, location of the North Celestial Pole, and the location of the North Star, Polaris. What is the altitude of the North Celestial Pole for an observer in Eugene, OR? What is the maximum altitude reached by the Celestial Equator in Eugene, OR?
5. What is the Synodic month? How is the length of the synodic month (month of the phases of the Moon) determined? At what time does the Full Moon rise? At what time does the full moon set? What is the sidereal month? What causes the difference between the lengths of the Synodic and Sidereal months? Does the moon rise earlier or later from night to night?
6. What causes the differences between the Solar Day and the Sidereal Day? Does a given star rise earlier or later from day to day? 7. In what month is the Earth closest to the Sun in its orbit? Farthest from the Sun? At what part of its orbit is the difference between the Solar Day and the Sidereal Day the greatest?
8. What are diurnal circles? What motion accounts for the diurnal motions? Sketch the diurnal circles for an observer in Eugene, OR, latitude ~ 44o North. Describe the diurnal circles for an observer at the North Pole, the South Pole, the Equator.
9. What is a tidal force (differential force)? Use a diagram (and words) to explain why there are two high tides per day on an ideal Earth. If the moon is full, roughly, at what time(s) will high tide occur? As a result of tides, how are the rotational period of the Earth and orbital period of the Moon changing?
10. On what day of the year are the hours of daylight the greatest for an observer in Eugene? On what day of the year does the Sun reach its greatest altitude above the horizon at local noon? On what day of the year does the Sun reach its lowest maximum altitude (during a day) above the horizon at local noon?
13. What are the principal orbital (dynamical) regularities of planetary motions any theory for the origin of the Solar System must explain? In what ways do these orbital regularities constrain how we think about the way in which the Solar System formed?
14. What is annual trigonometric stellar parallax? What were the proposed explanations for the ancient Greek's lack of observed annual trigonometric parallax? What is the current interpretation for the ancient Greek's negative result on annual trigonometric parallax? What was Copernicus's interpretation for the ancient Greek's result?
15. What are Kepler's 3 Laws of Planetary Motion? Qualitatively, what do each of Kepler's laws tell us? What is an ellipse? How are circles and ellipses related? What is meant by sidereal oribtal period? What is Kepler's second law of planetary motion and how does it allow us to figure how the speed of a planet in its orbit varies? What is Kepler's third law of planetary motion? How does it tell us about how fast different planets move in their respective orbits?
16. What was Tycho's most significant contribution to modern astronomy?
17. Compare and contrast the models of Ptolemy (geo-centric) and Copernicus (helio-centric) for the Solar System. Which was favored by the obervations at the time? Why were Helio-centric models rejected by the ancient Greeks? How are the ancient Greek's objections currently overcome? Compare and contrast how Ptolemy and Copernicus explained Retrograde Motion.
18. How was the question of geo-centric vs. helio-centric settled? Outline the issues and the steps followed which allowed us to choose between the two models. What were the roles played by Tycho Brahe, Johannes Kepler, and Isaac Newton?
20. What were the reasons Copernicus's heliocentric theory was not universally embraced?
21. What are morning and evening stars? What is the explanation for morning and evening stars? Which planets go through a complete cycle of phases (similar to the Moon's phases)?
22. Explain the cause for the seasonal variations on the Earth. What angle does the rotation axis of the Earth make with the normal to the ecliptic plane? What would happen to the seasonal variations on the Earth if there was no misalignment between the orbital axis and spin axis of the Earth?
24. What were some of the significant contributions of the ancient Greeks, e.g., what did Aristarchus and Erastosthenes contribute to astronomy?
27. What were the reasons Copernicus's heliocentric theory was not universally embraced? What arguments did Aristarchus use to bolster his heliocentric model for the Solar System? How did Copernicus and Aristarchus overcome the lack of an observed annual trigonometric parallax?
28. How did the ancient Greeks infer that the Earth was spherical in shape? How did the ancient Greeks determine the circumference of the Earth?
29. What is meant by Universal Gravitation?