Download Homework 3 Answers for Astronomy - Fall 2005 | AST 192 and more Assignments Astronomy in PDF only on Docsity! Astronomy 192. Homework 13. Due Wednesday, April 20, 2005. Name ________________________KEY________________________ Student Number (4 digits only) _____0000___________________ This is sort of a review. Part I. (20 points) 1. In the first column of the Table below, list your Cosmic Address, starting with the smallest and ending with the largest scale. This list should include (A) the Local Group, (B) the Solar System, (C) the Milky Way, (D) the Orion Spiral Arm, (E) the Virgo Supercluster, and (F) the Solar Neighborhood. 2. In the second column of the Table below, write the corresponding length scale in light-years. Precise answers are not required, it is enough to try to get the power of 10 as near as possible. For example, the Solar System is approximately 10-3 lys in size. 3. In the third column of the Table, write the measurement technique most useful for determining the distance from Earth of objects in that row of the Table. For example, for objects in the Solar System, radar is the best technique. If more than one technique is applicable, write them both. The choices are: Radar, Cepheid Variable Stars, Parallax, Hubble’s Law, Main Sequence Fitting, the Tully-Fisher relation and White-Dwarf Supernovae. Cosmic Address Length Scale Measurement technique Solar System 10-3 lys Radar Solar Neighborhood 102 lys Parallax Orion Spiral Arm 104 lys Main Seq. Fitting Milky Way 105 lys Main Seq. Fitting Local Group 107 lys Cepheid Variable Virgo Supercluster 1010 lys Tul. Fis. & WDS Part II. (20 points) 1. In the Table below, list the following phenomena in order of increasing time scale (that is, starting with the phenomenon that occurs in the shortest period of time.) The elements in the list should include (A) one Earth orbit around the Sun, (B) one Earth rotation on its axis, (C) one Solar Orbit of the Milky Way, (D) one Precession of the Earth’s axis, (E) one Lunar cycle, (F) the formation of the Milky Way Galaxy, and (G) the birth of the Sun. 2. In the second column of the Table, write the corresponding time scale in years. Precise answers are not required, just try to get the power of 10 right. For example, one Earth rotation on its axis requires 1/365th or 10-2 years. 3. In the third column of the Table, write the month of the Cosmic Calendar in which the event (or the last occurrence of the event) took place. You need only indicate the month. Phenomenon Time Scale Cosmic Calendar Month Earth rotation 10-2 yrs December Lunar Cycle 10-1 yrs December Earth orbit around Sun 1 yr December Precession of Earth 104 yrs December Sun Orbits Milky Way 108 yrs December Birth of the Sun 109 yrs September Milky Way Formation 1010 yrs February
