ASTR 101-220 Fall 2024 Descriptive Astronomy Test 1 Study Guide PDF

1 ASTR 101-220, Fall 2024 — Descriptive Astronomy Study Guide for Test 1 to be held Wednesday, September 18, 2024, from 1 pm to 2 : 15 pm in F-1001. You will not be given extra time if you arrive late. Please bring a calculator, a number 2 pencil and an eraser to the test. You w...

1 ASTR 101-220, Fall 2024 — Descriptive Astronomy Study Guide for Test 1 to be held Wednesday, September 18, 2024, from 1 pm to 2 : 15 pm in F-1001. You will not be given extra time if you arrive late. Please bring a calculator, a number 2 pencil and an eraser to the test. You will not be allowed to use the calculator on your cellphone, computer, tablet, smartwatch or other communication device. All computers, tablets, cellphones and other communication devices must be turned off during the test. You will not be allowed to wear sunglasses, a cap or hood, or use headphones to listen to music or other audio. You will be asked to place your scantron form in a cover, and you could be assigned a seat in the fixed seats or at one of the tables at the front of the room. The test will consist of 40 – 50 multiple choice questions. A few recommendations: Since you have already read the material from the textbook at least once, I would recommend that you read through the PowerPoint slides that are on iCampus and your notes first. Then go through all the tutorials listed below. Re-read the textbook as needed. Write down answers to the end of chapter questions listed below, especially the ones in the “review questions” category, without looking at any materials or getting any help. Also go through the homework at MyLab and Mastering. If questions arise as you study, then get them cleared up by contacting your instructor. If you wish to look over quiz questions and think-pair-share questions, then you will need to see your instructor during office hours or by appointment. It is best to distribute your studying over several days so you can remember and recall the material without too much difficulty. Do not study for several hours the day or night before the test as you need to get enough rest the night before so you do not feel tired during the test. You can also look at pages xx and xxi of the text for recommendations on how to study. Some of my past students have found studying from the print version of the textbook more beneficial than the electronic version. You can rent a copy of the textbook from the JJC bookstore if you wish. The bullet points and notes provided below are not meant to comprehensively cover all that is in our textbook, our workbook and what we covered in class. You can write your own notes if you wish, instead of using the ones here. Good luck. Here’s what you will be given in the test: 1 AU = 1.496 × 1011 m 1 light year = 9.46 × 1015 m distance traveled Speed of light = 3 × 108 m/s Speed = time elapsed A. Reading for Test 1: “A few mathematical skills” – Appendix C (pages A-3 – A-7) “Constellations and Star Charts” – Appendices H and I (pages A-17 – A-23) Chapter 1 Chapter 2: Sections 2.1, 2.2 Chapter 15: pages 389, 390, and first paragraph on page 391 B. Tutorials from the workbook: Since our workbook is very important it is essentially an addition to our textbook. The tutorials we have covered so far are Looking at Distant Objects  2 Questions 1 – 7, Path of the Sun Questions 1 – 5 and remaining tutorial questions are on green sheet), Seasons (do at home) C. Other Study Materials: From MyLab and Mastering: Homework 1 on Chapter 1 and Section 15.1 pages 389, 390, and first paragraph on page 391, Homework 2 on Seasons Chapter 1 end of chapter questions from Exercises and Problems (pages 21, 22): 1, 2, 3, 4, 5, 9, 10, 13, 14, 15, 16, 17, 18, 19, 21, 23, 24, 25, 26, 27, 30, 31; also work through the ”See it for yourself” item on page 6 End of Chapter 2 (pages 50, 51, 52): Visual Skills Check, Questions from Exercises and Problems – 1 (“What are constellations?” only), 4, 7 (“What are latitude and longitude?” only), 8, 9, 10, 24, 27, 31, 32, 44 also work through the ”Think about it” questions on pages 29 and 33, and the ”See it for yourself” question on page 31. End of Chapter 15 Questions from Exercises and Problems (page 411): 1, 16, 26, 27 Ranking Task handout on Size and Distance – look under Module 6 in Canvas, and enter your answers there too. ClassAction questions on Chapter 1 listed in Module 6 in Canvas. “Sun at noon” animation to learn about where the Sun rises and sets on different days of the year, how the noon position of the Sun changes throughout the year, and your shadow’s direction and length at noon. This is for the continental US. Details on how to obtain and use this are in Module 7 (“Constellations, Path of the Sun, Shadows and Seasons” module) in Canvas. Animation on sunrise and sunset position throughout the year that is in the list of animations in Module 7 in Canvas Complete the Seasons self-guided tutorial at MyLab and Mastering. You can go to the Practice Tutorials assignment that is open till December 11 to find this. There are no points associated with this. Interactives (ranking tasks) and ClassAction questions on Seasons listed in Module 7. PowerPoint slides on Canvas I. Chapter 1, Chapter 15 Section 15.1 pages 389, 390, first paragraph on page 391: ˆ Definition of planet, moon, asteroid, comet, dwarf planet, solar system, star, nebula, galaxy, cluster of galaxies, supercluster of galaxies, universe ˆ our cosmic address ˆ Units of measurement for time (seconds, hours, days, years) and distance (meters, kilometers, miles, inches, et cetera) ˆ One Astronomical Unit = average distance between Earth and Sun = 1.496 × 1011 m ˆ One Light Year = distance that light travels in one year = 9.46 × 1015 m The definition of the light year is such that for an object that is 10 light years away, we immediately know that it takes light 10 years to travel from that object to us. We see distant objects as they were in the past. distance traveled ˆ Speed = time elapsed ˆ speed of light = 3 × 108 m/s  3 ˆ Voyage Model of solar system ˆ one day, one year, rotation, orbital motion ˆ structure, size and shape of Milky Way Galaxy, and location of the Sun in our Galaxy — See Figure 15.1 page 389, and text on pages 389, 390, and first paragraph of page 391. ˆ age of solar system, age of universe II. Chapter 2 Section 2.1 ˆ Constellations – regions of the sky, there are 88 constellations that cover the entire sky. ˆ local horizon: north, south, east, west; zenith; meridian ˆ Position of stars and astronomical objects are determined using compass directions (NSEW) and height above horizon (near horizon/low in sky/near the ground, high, directly over- head/highest in the sky) ˆ Earth is a sphere – latitude, longitude define places on Earth ˆ Earth spins on its rotation axis while also orbiting the Sun. ˆ The Sun’s path in the sky over the course of one year is called the ecliptic. The thirteen constellations the Sun travels through over the course of one year form the constellations of the zodiac. ˆ The position where Sun rises and sets changes during the year. It rises due east and sets due west on March 21 and September 21. From March 22 to September 20 it rises north of east and sets north of west. From September 22 to March 20 it rises south of east and sets south of west. ˆ Sun is highest in sky at noon each day. For the continental US, at noon, the Sun is in the southern sky. Height of Sun at noon varies over the course of the year. The Sun is highest at noon (and highest for the year) on June 21 and lowest at noon on December 21 for the whole year. ˆ For the continental US, the Sun is never overhead. ˆ The day with the greatest number of daylight hours is the summer solstice. For the northern hemisphere, the summer solstice falls on June 21. ˆ The day with the least number of daylight hours is the winter solstice. For the northern hemisphere, the winter solstice falls on December 21. ˆ The days when the number of daylight hours = nighttime hours = 12 are the days of the equinoxes. March 21 is the vernal/spring equinox and September 21 is the fall/autumnal equinox for the northern hemisphere. ˆ Shadows of objects placed vertically in/on the ground are longest when the sun is close to the horizon, for example, sunrise; and are shortest when the sun is high in the sky, for example, noon. The shadow of an object is formed on the opposite side of the object from the light source. See figure on next page.  4 ˆ Noon shadows for the continental US: The noon shadow of objects placed vertically in/on the ground alway points to the north. The length of the noon shadow is longer when the noon Sun is lower in the sky, and is shorter when the noon Sun is higher in the sky. The longest noon shadow occurs on December 21 at noon and the shortest noon shadow occurs on June 21. There is always a shadow present! Shadows are always located on the opposite side of the object from the Sun is light source i.e. the Sun and the high in object’s shadow are not on the same the sky (a) side of the object, or if you are facing the Sun, your shadow is behind you. Object = Flagpole or you standing up object or a stick planted vertically in the ground Horizontal arrow = Shadow Shadow is short when the Sun is high in the sky e.g. at noon (b) Sun is low in the sky object Horizontal arrow = Shadow Shadow is long when the Sun is low in the sky e.g. at sunrise and sunset ˆ Tilt of Earth’s equator to its orbital plane creates seasons. The angle between the Earth’s equator and its orbital plane is 23.5◦. Or the angle between the Earth’s rotation axis and the perpendicular to its orbital plane is 23.5◦. Northern summer occurs when north pole points to sun, the number of daylight hours are greatest and while the hours of darkness are few. Temperatures are high in summer because Sun’s rays hit more directly (vertically) and because Sun is above the horizon longer. The  5 longest number of daylight hours occurs at the summer solstice, which is June 21. Northern winter occurs when north pole points away from the sun, hours of daylight are few while hours of darkness are high. Temperatures are low in winter because Sun’s rays hit less directly and because the Sun is above the horizon for a shorter period of time. The shortest number of daylight hours for the northern hemisphere occurs at winter solstice, December 21st. In between the solstices are the equinoxes, when day and night are of equal length. Equinoxes occur on March 21 and September 21 as mentioned above. In the southern hemisphere, seasons are reversed. Distance from Earth to Sun varies slightly over the course of one year, but that is not the cause for seasons. ˆ All planets, except Venus, have seasons because their equators are tilted with respect to their orbital planes.