# I. Introduction: II. Maps of the Earth: NAME: COORDINATE SYSTEMS. What will you learn in this Lab?

Save this PDF as:

Size: px
Start display at page:

Download "I. Introduction: II. Maps of the Earth: NAME: COORDINATE SYSTEMS. What will you learn in this Lab?"

## Transcription

1 NAME: COORDINATE SYSTEMS What will you learn in this Lab? This lab is designed to introduce you to some of the coordinate systems used by astronomers. The coordinate systems to be introduced are Longitude and Latitude, Horizon Coordinate System, Equatorial Coordinate System and the Ecliptic Coordinate System. What do I need to bring to the Class with me to do this Lab? For this lab you will need: A copy of this lab script A pencil SC 001/002 star charts Audubon Guide Star Wheel Red Flashlight I. Introduction: This lab is introduces some of the coordinate systems used by astronomers. First, we will review the coordinate system used here on the Earth, using longitude and latitude. Then, we will investigate two of the coordinate systems applied to astronomical maps. The coordinate systems to be introduced are: (1) the Horizon Coordinate System, measuring the sky in altitude and azimuth from the location of the observer; and (2) the Equatorial Coordinate System, measuring the right ascension and declination coordinates fixed to the stars. II. Maps of the Earth: As a starting point for finding your way in the night sky, we first review maps of the Earth and how they were established. A coordinate reference frame is essential so that the location of remote places can be identified, such as islands at sea, cities, towns, mountain tops, etc. On the Earth the coordinate system employs latitude and longitude Arizona State University Page 1 of 17

2 Latitude: Latitude is measured in degrees, arcminutes and arcseconds, north or south of the Earth s Equator. The zero point in latitude is naturally established by how the Earth rotates on its axis. The Earth s Equator is at a latitude of 0º, while the north pole is at a latitude of 90º N (aka +90º). Similarly, the south pole is at a latitude of 90º S (aka -90º). Tempe, Arizona is at a latitude of +33º. Longitude: Longitude is also measured in degrees, arcminutes and arcseconds, but unlike latitude there is no natural or physical characteristic of the Earth from which to set the zero point in longitude. As a result of global navigation, and what is now history, the British established a zero point in longitude in Greenwich, England at the Greenwich Royal Observatory. The Royal Observatory at Greenwich was established along the Thames River in 1676 for purposes of worldwide navigation. A ship s navigator on the Thames checked the time from clocks at the Royal Observatory as the ship set out to sea. While out at sea, the navigator measured the position of the sun at noon (according to the shipboard clock). For a westward-moving ship, the navigator calculated the angular distance between the sun (to the east) and the local meridian 1 at noon to determine the ship s longitude west of Greenwich. Historically various countries established their own zero point of longitude, which is given the name: zero meridian. National observatories were established in Paris, London, Berlin, Leningrad, Madrid, and other major capitols with the purpose of determining longitude. By 1889, through international agreement, most countries adopted the Greenwich Meridian as a standard of longitude. III. Maps of the Sky: Horizon Coordinate System Before introducing the principal celestial coordinate system, it is useful to discuss a more local coordinate system. This coordinate system is established with natural reference to the observer and his/her location and has two coordinates both measured in degrees, arcminutes and arcseconds. Azimuth: Azimuth is the angular distance measured along the horizon from 0º to 360º, just like a clock. An azimuth of 90º corresponds to the east point on the horizon (3 o clock), while 270º points towards the west point on the horizon (9 o clock). 1 A meridian is a circle on the Earth s surface that has its center at the center of the Earth and passes through the north and south poles Arizona State University Page 2 of 17

3 Altitude: Altitude is measured as an angular distance from the horizon toward the point directly overhead, called the zenith. Thus the zenith is at an altitude of 90º, whereas the horizon is at an altitude of 0º. Since we cannot use linear dimensions on the sky, all positions must be measured as angles. Zenith Sky S 45 W E 90 Figure 1 N Observer's Horizon Estimating Distances You can use your hands to estimate angular distances in the sky. Make your hand into a fist, and hold it far away from your body, toward the sky. The angular distance your hand spans on the sky is about 10º. So, if a star appears just to the left side of your fist and another star appears just to the right of your fist, those stars are approximates 10º angular distance from each other on the sky. Here are some other distance estimates which may help you in tonight s lab 2 : Figure 2 2 This image borrowed from the One Minute Astronomer Arizona State University Page 3 of 17

4 Changing Locations Unfortunately, we cannot use altitude and azimuth coordinates to find the same object in the sky every night. The Earth rotates on its axis and revolves around the Sun, and consequently, we cannot map positions on the sky as simply as we would map positions on the Earth. Since the Earth gradually orbits around the Sun, the direction that we look out from the Earth into the night sky gradually shifts day by day, changing by about 1º per day. This corresponds to about 4 minutes of time. In the course of a year, the Earth moves through 360º. Most of the newly built large telescopes use this system for pointing and use fast computers to make sure the telescope moves in the correct direction at the correct rate of motion. It is all about the reference point of the coordinate system. In the Horizon System, the observer is the reference point. The position of the sky changes with respect to the observer, so the location of the stars in altitude and azimuth also changes. IV. Maps of the Sky: Equatorial Coordinate System Unlike the Horizon Coordinate System, which is established by the reference point of the observer, the Equatorial Coordinate System is fixed to the stars. As an extension of our Earth-based coordinate system, the Equatorial Coordinate System is a similar set of coordinates on the sky. The Celestial Equator is a projection of the Earth s equator onto the sky, but where the Earth s equator is fixed to the Earth, the Celestial equator if fixed to the stars. Similarly, directly above the Earth s north pole is the north celestial pole (NCP), while directly below the Earth s south pole is the south celestial pole (SCP). The celestial coordinates that are analogous to latitude and longitude (on Earth) are called declination and right ascension (on the sky). Declination (Dec) Declination (Dec) is similar to the Earth-based system of latitude. Like latitude, Dec is measured in degrees, arcminutes and arcseconds, north or south of the Celestial equator. The Celestial equator is at a declination of 0º, while the north celestial pole (Polaris!) is at a declination of 90º N (aka +90º). Similarly, the south celestial pole is at a declination of 90º S (aka -90º). In Tempe, Arizona, if you were to point to your zenith, you would be pointing to a declination of +33º on the sky. Right Ascension (RA) Right ascension (RA) is measured in units of time: hours, minutes and seconds. RA is measured in an eastward direction, starting at 0 hrs and going through a full circle to 24 hrs. In 1 hr of time, the sky moves through 1 hr of right ascension. Similarly, in 4 min of time the sky moves through 4 min of RA. On the celestial equator, 4 min of RA corresponds to a 1º movement of the sky. Similarly, 1 hr of RA corresponds to a 15º movement of the sky, and 24 hrs of RA corresponds to a full 360º rotation of the Earth when measured at the celestial equator Arizona State University Page 4 of 17

5 The zero point of RA is established by the point where the Ecliptic 3 crosses the celestial equator. Because the Earth is tilted with respect to the Sun, the Sun does not to follow a straight path through the sky. Instead, it moves northward from December to June and southward from June back to December. In June, the Sun reaches a Dec of +23.5º (the Tropic of Cancer). In December, the Sun reaches a Dec of -23.5º (the Tropic of Capricorn). On March 21 st (the spring equinox) and September 21 st (the fall equinox), the Sun passes over the Celestial equator, where the declination is 0º. We define the zero point of right ascension as the point in the sky where the Sun crosses the Celestial equator in the spring when the Sun crosses the celestial equator moving northward. Figure 3 3 The ecliptic is the apparent path of the Sun, Moon, and planets as seen from the Earth. In another sense, the ecliptic is the path of the Earth s orbit projected onto the sky. The orbits of the Earth and most of the other planets move in a relatively flat plane around the Sun Arizona State University Page 5 of 17

6 Fixed Locations Because RA and Dec are coordinates fixed to the sky, stars and other distant objects will keep their location in right ascension and declination throughout the year (just like we stay at the same latitude and longitude here in Tempe). Take, for example, the star Betelgeuse, in the Orion constellation. Betelgeuse has Equatorial coordinates of approximately (RA = 6h and Dec = +7.5 ). Because Equatorial coordinates are fixed to the stars, Betelgeuse will always have these coordinates. The RA and Dec of the stars do NOT change throughout the year. This is different from the Horizon System, where the altitude and azimuth of the stars will change over the course of the night. This difference is inherently a question of reference point. In the Equatorial Coordinate System, the coordinates are fixed relative to the stars. While our view of the stars may change over the course of the night or over the course of the year, the location of those stars in the sky remain fixed with respect to the other stars. This means that the right ascension and declination of the stars will also stay fixed throughout the year! V. The Experiment: Outdoor Observations Marston Theater 3D Planetarium During this lab, we will visit the Marston Theater in Interdisciplinary Building IV (ISTB4). The Marston Theater is ASU s 3D Planetarium Theater, and the wonderful folks who run the planetarium will explain these coordinate systems by drawing critical lines and axes on the virtual 3D sky for you to visualize. Then you can hold these in your mind s eye when you subsequently look at the night sky outside. Part 1: Observing Stars in the Horizon Coordinate System Page 11 has a table in which you should record your observations. There are a variety of methods to measure the altitude and azimuth of stars and distant objects. In this lab, you will use a protractor and a plumb-bob to measure altitudes and knowledgeable estimation to measure the azimuths. (Remember that you can make estimates using your hands!) With one of the protractors, look along the long flat edge of the protractor and line it up with the object that you are looking at. Hold down the location of the string and read off the larger angle given by the protractor THEN SUBTRACT 90 o, this will be the altitude of the object. Note: You CANNOT use the protractor to measure altitudes greater than 90, and you MUST read the larger angle. Record the name of the object, the time of the observation, and the measured altitude in the table on page Arizona State University Page 6 of 17

8 Part 2: Finding Stars in the Equatorial Coordinate System Inside of the classroom, using your SC charts, determine the right ascension and declination for each of the stars you observed. Record the RAs and Decs for each of these stars in the table on page 11. Q3. Will the RAs and Decs of your observed objects change tonight? Why or why not? Q4. Now we re going to think about how much a star will move in a given time and why RA has units of time. Choose a star that was near your meridian. a. What is the RA of this star to the nearest hour? At what time did you make your observation to the nearest half hour? b. At what time will the star move to a position 45 away from the meridian? Hint: Remember that 1hr of RA is equal to 15 on the sky. c. At this new time, what will be the RA of the stars now at the meridian? How did you determine your answer? d. In 5 more hours, what will be the RA of the stars at the meridian? How far (to the nearest degree) will your original star be from the meridian at this point in time? 2015 Arizona State University Page 8 of 17

9 On your long star chart, you will notice a sinusoidal (curvy) line going through the middle. This is the ecliptic, which traces out the path of the Sun through the course of the year. Unlike the other stars in the sky, which are far away, the Sun is not at a fixed position in the Equatorial Coordinate System. Because the Sun is closer to us than the stars, its movement is faster, and the Sun s position in RA and Dec changes throughout the year. Look at the Sun s path through the star chart and answer the following questions in complete sentences. Q5. How many RA-hours does the Sun travel through per year? Q6. By how many RA-mins does the position of the Sun change per day? Hint: Take the previous answer and convert (calculation) Q7. Why are the Moon and planets not located on the SC charts or star wheel? That they are not stars is NOT an answer! Q8. What is the RA and Dec of the Sun at the time of the spring equinox? During the fall equinox? Q9. What is the RA and Dec of the Sun at the time of the summer solstice? During the winter solstice? 2015 Arizona State University Page 9 of 17

10 Q10. Zodiacal constellations are constellations along the ecliptic, near the path of the Sun. What was the zodiacal constellation on the meridian at 8 pm tonight? Hint: You may find your star wheel helpful. Part III: Observing Stars (Again!) in the Horizon Coordinate System An hour after your first observation, measure the altitudes and azimuths of the same 5-10 stars you measured earlier. Record these measurements in the table. Q11. How well did your new altitudes and azimuths follow your predictions? If there were stars whose altitude or azimuth changed in a way you did not predict, explain what happened to cause this movement. If all the stars followed the path you expected, explain how you were able to accurately predict their movement. VI. Conclusion: Summarize the concepts you learned about in tonight s lab. What did you learn about each of these concept? Summarize the experiment. How did this experiment help you understanding of the concepts? 2015 Arizona State University Page 10 of 17

11 Object 1 st Obs. Time: Alt(1) Az(1) Predicted Movement Alt Az RA DEC 2 nd Obs. Time: Alt(2) Az(2) 2015 Arizona State University Page 11 of 17

12 V. The Experiment: Indoor Alternative Marston Theater 3D Planetarium During this lab, we will visit the Marston Theater in Interdisciplinary Building IV (ISTB4). The Marston Theater is ASU s 3D Planetarium Theater, and the wonderful folks who run the planetarium will explain these coordinate systems by drawing critical lines and axes on the virtual 3D sky for you to visualize. Part 1: Horizon Coordinate System Answer the following questions about the Horizon Coordinate System. Q1. The altitude and azimuth of the stars will change over the course of the night. Why is this? Q2. In the table below, we have listed the altitude and azimuth of several madeup stars. Assume these observations were made at 8pm tonight. For each of the stars below, state whether the altitude and azimuth will increase, decrease, or stay the same if we were to measure them again at 10pm. Hint: They may not all be the same! How each coordinate changes depends on where the object began. Measured Coordinates Predicted Change (Increase, Decrease, Same) Star Alt Az Alt Az A B C 33 0 D E 0 45 F G H Arizona State University Page 12 of 17

13 Q3. For the stars in the table above, justify why you chose increase, decrease, or stay the same for each of these stars. Q4. Looking at the stars in the chart above, will these measured value for altitude and azimuth be the same from another location on Earth? Why or why not? At what latitude on Earth would you need to be to see each of these stars at the zenith? Q5. Which stars will change their position most ones near the Celestial equator or ones near the pole? Explain. Part 2: Equatorial Coordinate System Your TA will give you the name of 5-10 stars or objects in the sky. Using your SC charts, determine the right ascension and declination for each of these objects. Record the RAs and Decs for each of these stars in the table on page 11. Q6. Will the RAs and Decs of these objects change over the course of a night? Over the course of a year? Why or why not? 2015 Arizona State University Page 13 of 17

14 Q7. The meridian is an imaginary line passing from the North Pole to the South Pole through your zenith. By this definition, any star at your zenith is also on the meridian. On your star wheel, the meridian can be found by drawing an imaginary line connecting the north and south directions of your chart. Use your star wheel and find a bright star near the meridian tonight at 8pm. a. What is the RA of this star to the nearest hour? b. At what time will the star move to a position 45 away from the meridian? Hint: Remember that 1hr of RA is equal to 15 on the sky. c. At this new time, what will be the RA of the stars at the meridian? How did you determine your answer? d. In 5 more hours, what will be the RA of the stars at the meridian? How far (to the nearest degree) will your original star be from the meridian at this point in time? Q8. Consider Hercules and Ophiuchus. Both constellations have an RA approximately equal to 17 hr. Hercules has a declination of about +30, while Ophiucus has a declination of about 0. Which of these constellations will get closer to the zenith in Tempe? How do you know? 2015 Arizona State University Page 14 of 17

15 On your long star chart, you will notice a sinusoidal (curvy) line going through the middle. This is the ecliptic, which traces out the path of the Sun through the course of the year. Unlike the other stars in the sky, which are far away, the Sun is not at a fixed position in the Equatorial Coordinate System. Because the Sun is closer to us than the stars, its movement is faster, and the Sun s position in RA and Dec changes throughout the year. Look at the Sun s path through the star chart and answer the following questions in complete sentences. Q9. How many RA-hours does the Sun travel through per year? Q10. By how many RA-mins does the position of the Sun change per day? Hint: Take the previous answer and convert (calculation) Q11. Why are the Moon and planets not located on the SC charts or star wheel? That they are not stars is NOT an answer! Q12. What is the RA and Dec of the Sun at the time of the spring equinox? During the fall equinox? Q13. What is the RA and Dec of the Sun at the time of the summer solstice? During the winter solstice? 2015 Arizona State University Page 15 of 17

16 Q14. Zodiacal constellations are constellations along the ecliptic, near the path of the Sun. What was the zodiacal constellation on the meridian at 8 pm tonight? Hint: You may find your star wheel helpful. Part III: All Together! In the space below, draw a dome like that shown in Figure 1 to represent the view from here in Tempe. Label the cardinal directions (N,E,S,W) Mark the position of Polaris. Hint: Tempe s latitude is +33. Draw the Celestial equator onto your dome. Draw a star on your Celestial equator. Think about how the stars will move over the course of the night. Mark this direction with an arrow. Circle which star (Polaris or the star on the Celestial equator) which moves the least over the course of the night. Box which star (Polaris or the star on the Celestial equator) which moves the most over the course of the night Arizona State University Page 16 of 17

17 Q15. Which coordinate system uses the observer as the reference point? Do the coordinates of the stars change over the course of a night in this system? Q16. Which coordinate system uses the stars as the reference point? Do the coordinates of the stars change over the course of the night in this system? VI. Conclusion: Summarize the concepts you learned about in tonight s lab. What did you learn about each of these concept? Summarize the experiment. How did this experiment you re your understanding of the concepts? 2015 Arizona State University Page 17 of 17

### Today. Appearance of the Sky. Orientation. Motion of sky. Seasons. Precession. Phases of the Moon

Today Appearance of the Sky Orientation Motion of sky Seasons Precession Phases of the Moon The Appearance of the Sky The Local Sky An object s altitude (above horizon) and direction (along horizon) specify

### Observational Astronomy - Lecture 1 Introduction, Distances and Angles, Coordinates

Observational Astronomy - Lecture 1 Introduction, Distances and Angles, Coordinates Craig Lage New York University - Department of Physics craig.lage@nyu.edu January 27, 2014 1 / 19 Observational Astronomy

### Celestial Coordinate Systems

Celestial Coordinate Systems Craig Lage Department of Physics, New York University, csl336@nyu.edu January 6, 2014 1 Introduction This document reviews briefly some of the key ideas that you will need

### UCCS PES 1090: Astronomy Lab I Spring/Summer/Fall Celestial Sphere name:

UCCS PES 1090: Astronomy Lab I Spring/Summer/Fall Celestial Sphere name: 1. What is the celestial sphere? a. An observatory dome. b. The Sun. c. The Earth. d. The imaginary sphere in the sky, on which

### Orientation to the Sky: Apparent Motions

Chapter 2 Orientation to the Sky: Apparent Motions 2.1 Purpose The main goal of this lab is for you to gain an understanding of how the sky changes during the night and over the course of a year. We will

### OBJECT: To become familiar with some of the motions of the stars, Sun, Moon and planets as seen from the surface of the Earth.

INSIDE LAB 2: Celestial Motions OBJECT: To become familiar with some of the motions of the stars, Sun, Moon and planets as seen from the surface of the Earth. DISCUSSION: As seen from a point of view centered

### Activity 1: What is latitude and longitude?

Activity 1: What is latitude and longitude? Background information The voyages of European navigators about 500 years ago led to the establishment of shipping routes and the need for accurate maps and

### The Celestial Sphere. Questions for Today. The Celestial Sphere 1/18/10

Lecture 3: Constellations and the Distances to the Stars Astro 2010 Prof. Tom Megeath Questions for Today How do the stars move in the sky? What causes the phases of the moon? What causes the seasons?

### ASTR 693A Coordinate systems

ASTR 693A Coordinate systems The following notes contain the essential information you ll need to understand where astronomical sources are in the sky. Further details can be found in Textbook on Spherical

### Basic Coordinates & Seasons Student Guide

Name: Basic Coordinates & Seasons Student Guide There are three main sections to this module: terrestrial coordinates, celestial equatorial coordinates, and understanding how the ecliptic is related to

### Introduction to the sky

Introduction to the sky On a clear, moonless night, far from city lights, the night sky is magnificent. Roughly 2000 stars are visible to the unaided eye. If you know where to look, you can see Mercury,

### Celestial Observations

Celestial Observations Earth experiences two basic motions: Rotation West-to-East spinning of Earth on its axis (v rot = 1770 km/hr) (v rot Revolution orbit of Earth around the Sun (v orb = 108,000 km/hr)

### Celestial Coordinates I

Equipment: Star Charts, Planisphere. Celestial Coordinates I Objective: To become acquainted with basic navigation of the night sky. Discussion: From our vantage point on Earth, the night sky has the appearance

### Sun Earth Relationships

1 ESCI-61 Introduction to Photovoltaic Technology Sun Earth Relationships Ridha Hamidi, Ph.D. Spring (sun aims directly at equator) Winter (northern hemisphere tilts away from sun) 23.5 2 Solar radiation

### Solar Angles and Latitude

Solar Angles and Latitude Objectives The student will understand that the sun is not directly overhead at noon in most latitudes. The student will research and discover the latitude ir classroom and calculate

### Celestial Sphere. Celestial Coordinates. Lecture 3: Motions of the Sun and Moon. ecliptic (path of Sun) ecliptic (path of Sun)

Lecture 3: Motions of the and Moon ecliptic (path of ) ecliptic (path of ) The 23.5 degree tilt of Earth s spin axis relative to its orbital axis around the causes the seasons Celestial Sphere Celestial

### Project Telling time by the stars Due April 28

Project Telling time by the stars Due April 28 1 As discussed in class, a useful celestial coordinate system for observers on the Earth is that of equatorial stellar coordinates. The two coordinates are

### Newton s Law of Gravity

Gravitational Potential Energy On Earth, depends on: object s mass (m) strength of gravity (g) distance object could potentially fall Gravitational Potential Energy In space, an object or gas cloud has

### Where on Earth are the daily solar altitudes higher and lower than Endicott?

Where on Earth are the daily solar altitudes higher and lower than Endicott? In your notebooks, write RELATIONSHIPS between variables we tested CAUSE FIRST EFFECT SECOND EVIDENCE As you increase the time

### Aileen A. O Donoghue Priest Associate Professor of Physics

SOAR: The Sky in Motion y Life on the Tilted Teacup Ride Phases of the Moon Aileen A. O Donoghue Priest Associate Professor of Physics Kiva December 1997 October 27, 2009 Celestial Coordinates Right Ascension

### Astronomy 12 Unit Test Review Charting the Sky

Astronomy 12 Unit Test Review Charting the Sky Astronomer: Part I- Multiple choice: Answer each question by shading the most appropriate bubble. 01. Astronomy is the study of a. the stars and planets and

### Observing the Night Sky

Name(s): Date: Course/Section: Grade: Observing the Night Sky Objectives: Students will familiarize themselves with different methods for locating objects in the night sky and use star wheels, atlases,

### Douglas Adams The Hitchhikers Guide to the Galaxy

There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.

### Modeling the sky with the Farquhar Globe

Modeling the sky with the Farquhar Globe Learning Goals: Learn to use a model to visualize motions in the sky and understand relative apparent positions of Sun and stars. Evaluate the usefulness of the

### Stellarium a valuable resource for teaching astronomy in the classroom and beyond

Stellarium 1 Stellarium a valuable resource for teaching astronomy in the classroom and beyond Stephen Hughes Department of Physical and Chemical Sciences, Queensland University of Technology, Gardens

### A Dialogue Box. dialogue box.

The Sky An introduction and review 1. Open TheSky (version 6, the blue icon). The screen should show the view of the sky looking due south. Even if the sun is above the horizon, the sky will look black

### HELIOSTAT II - MEASURING THE SOLAR ROTATION

HELIOSTAT II - MEASURING THE SOLAR ROTATION SYNOPSIS: In this lab you will map sunspots, and from the movement of the spots over several days, you will determine the rotation rate of the Sun. EQUIPMENT:

### 1 Astronomical Coordinate Systems... Continued

General Astronomy (29:61) Fall 2012 Lecture 4 Notes, August 27, 2012 1 Astronomical Coordinate Systems... Continued 1.1 The Equatorial Coordinate System The most basic astronomical observation is that

### Astronomy 101 Lab: Seasons

Name: Lecture Instructor: Astronomy 101 Lab: Seasons Pre-Lab Assignment: In class, we've talked about the cause of the seasons. In this lab, you will use globes to study the relative positions of Earth

### Lab 2: The Earth-Moon System and the Sun and Seasons

Lab 2: The Earth-Moon System and the Sun and Seasons Moon Phases We heard lectures about the moon yesterday, so here we will go through some interactive questions for lunar phases. Go to http://astro.unl.edu/naap/lps/lps.html.

### CELESTIAL CLOCK - THE SUN, THE MOON, AND THE STARS

INTRODUCTION CELESTIAL CLOCK - THE SUN, THE MOON, AND THE STARS This is a scientific presentation to provide you with knowledge you can use to understand the sky above in relation to the earth. Before

### EDMONDS COMMUNITY COLLEGE ASTRONOMY 100 Winter Quarter 2007 Sample Test # 1

Instructor: L. M. Khandro EDMONDS COMMUNITY COLLEGE ASTRONOMY 100 Winter Quarter 2007 Sample Test # 1 1. An arc second is a measure of a. time interval between oscillations of a standard clock b. time

### AST 114 Spring 2016 Introduction to the Night Sky INTRODUCTION TO THE NIGHT SKY

NAME: INTRODUCTION TO THE NIGHT SKY What will you learn in this Lab? This lab will introduce you to the layout of the night sky: constellations and stars, their names and the patterns they make, and the

### INTRODUCTION TO THE TELESCOPE

AST 113/114 Fall 2014 / Spring 2016 NAME: INTRODUCTION TO THE TELESCOPE What will you learn in this Lab? For a few of the labs this semester, you will be using an 8-inch Celestron telescope to take observations.

### Chapter 2 Review Clickers. The Cosmic Perspective Seventh Edition. Discovering the Universe for Yourself Pearson Education, Inc.

Review Clickers The Cosmic Perspective Seventh Edition Discovering the Universe for Yourself The sky is divided into 88 zones called a) degrees. b) tropics. c) constellations. d) signs. The sky is divided

### Tropical Horticulture: Lecture 2

Lecture 2 Theory of the Tropics Earth & Solar Geometry, Celestial Mechanics The geometrical relationship between the earth and sun is responsible for the earth s climates. The two principal movements of

### ASTR 1030 Astronomy Lab 65 Celestial Motions CELESTIAL MOTIONS

ASTR 1030 Astronomy Lab 65 Celestial Motions CELESTIAL MOTIONS SYNOPSIS: The objective of this lab is to become familiar with the apparent motions of the Sun, Moon, and stars in the Boulder sky. EQUIPMENT:

### Written for version (Released 12/06/2010), using a Windows platform.

Stellarium Tutorial Written for version 0.10.6.1 (Released 12/06/2010), using a Windows platform. ABOUT STELLARIUM Stellarium is a free, open-source planetarium program for your computer. It shows a realistic

### 1. How many days each year does the Sun rise due East and set due West?

Motion of the Sun Student Page Purpose To examine the path of the Sun across the sky at different times of the year from different locations on the Earth, and study its effects at different locations.

### Earth-Sun Relationships. The Reasons for the Seasons

Earth-Sun Relationships The Reasons for the Seasons Solar Radiation The earth intercepts less than one two-billionth of the energy given off by the sun. However, the radiation is sufficient to provide

### Pre and post-visit activities - Navigating by the stars

Pre and post-visit activities - Navigating by the stars Vocabulary List Adult Education at Scienceworks Pre-visit Activity 1: What is longitude and latitude? Activity 2: Using the Southern Cross to find

### Field of View of a Small Telescope Observational Astronomy

Field of View of a Small Telescope Observational Astronomy Name: Introduction How much can you see? This question could be interpreted in several ways. An astronomer might answer in terms of the faintest

### Reasons for Seasons. Question: TRUE OR FALSE. Question: TRUE OR FALSE? What causes the seasons? What causes the seasons?

Reasons for Seasons Question: TRUE OR FALSE? Earth is closer to the Sun in summer and farther from the Sun in winter. Question: TRUE OR FALSE? Earth is closer to the Sun in summer and farther from the

### THE STARRY SKY AST MESA COMMUNITY COLLEGE

NAME: DATE: INTRODUCTION This lab exercise introduces the arrangement and motions of the stars, constellations, and other objects of the night sky. LEARNING GOALS Describe the motions of stars during a

### 1-2. What is the name given to the path of the Sun as seen from Earth? a.) Equinox b.) Celestial equator c.) Solstice d.

Chapter 1 1-1. How long does it take the Earth to orbit the Sun? a.) one sidereal day b.) one month c.) one year X d.) one hour 1-2. What is the name given to the path of the Sun as seen from Earth? a.)

### The Reasons for the Seasons

Guiding Question: What causes the seasons on Earth? The Reasons for the Seasons Vocabulary astrolabe equinox rotate axis horizon solstice elliptical revolve (orbit) sundial Materials Exploration (per group)

### Aphelion The point in the orbit of a planet or other celestial body where it is furthest from the Sun.

SKYTRACK Glossary of Terms Angular distance The angular separation between two objects in the sky as perceived by an observer, measured in angles. The angular separation between two celestial objects in

### Reasons for the seasons on Earth

Reasons for the seasons on Earth Background information The Earth orbits the Sun in a slightly elliptical path. This means that sometimes the Earth is slightly closer to the Sun than other times but this

### Lesson 4 The Seasons. There are 5 major zones on the earth.

In this lesson I will talk about what causes our four seasons, spring, summer, fall, and winter. I will cover this by telling some of the myths about what many think are the cause of our seasons and then

### Coordinate Systems. Orbits and Rotation

Coordinate Systems Orbits and Rotation Earth orbit. The earth s orbit around the sun is nearly circular but not quite. It s actually an ellipse whose average distance from the sun is one AU (150 million

### A model of the Earth and Moon

A model of the Earth and Moon Background Information This activity demonstrates the relative sizes of the Earth and Moon and the distance between them. The Moon is our nearest neighbour. It orbits the

### Worksheet Motion of the Sun and Moon

Worksheet Motion of the Sun and Moon Apparent Motion of the Sun 1. The Earth makes one complete orbit around the Sun in one year. From the point of view of someone on the Earth this makes the Sun appear

### Moon Phases. Grade Level: Eighth - Eleventh. Subject Areas: Earth Space Science. Timeline: One class period

Moon Phases Objectives: Students will model the phases of the moon Students will be able to explain why the moon s appearance changes Students will understand that only one side of the moon is ever visible

### Exercises Using a Planisphere

Astro 1H, Spring 2009 Dr. Richard Wade Exercises Using a Planisphere These Exercises use the Edmund Scientific Star and Planet Locator, an inexpensive planisphere. The Exercises gradually introduce the

### Whither does the Sun rove?

Whither does the Sun rove? Alejandro Gangui, IAFE/Conicet and University of Buenos Aires, Argentina If one asked some friends where on the horizon they should expect to see the sunrise, half of the answers

### ASTRONOMY 111 LABORATORY MANUAL

ASTRONOMY 111 LABORATORY MANUAL DR. TSUNEFUMI TANAKA PHYSICS DEPARTMENT CALIFORNIA POLYTECHNIC STATE UNIVERSITY DR. BRETT TAYLOR DEPARTMENT OF CHEMISTRY AND PHYSICS RADFORD UNIVERSITY FALL 2003 EDITION

### MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following statements about the celestial equator is true at all latitudes? A) It extends

### Today FIRST HOMEWORK DUE NEXT TIME. Seasons/Precession Recap. Phases of the Moon. Eclipses. Lunar, Solar. Ancient Astronomy

Today FIRST HOMEWORK DUE NEXT TIME Seasons/Precession Recap Phases of the Moon Eclipses Lunar, Solar Ancient Astronomy How do we mark the progression of the seasons? We define four special points: summer

### 2. EARTH AND THE SEASONS

2. EARTH AND THE SEASONS EQUIPMENT 12-inch diameter globe with tilted rotation axis and hour circle 12-inch diameter ring light Ring light stand and clamp Dark-colored towel Protractor with attached string

### .11 THE DAY. S it crosses the meridian at apparent noon. Before (ante) noon is thus a.m., while after (post) noon is p.m. FIGURE 7.

Confirming Pages UNIT 7 PA RT I The Time of Day From before recorded history, people have used events in the heavens to mark the passage of time. The day was the time interval from sunrise to sunrise,

### The Seasons on a Planet like Earth

The Seasons on a Planet like Earth As the Earth travels around the Sun, it moves in a giant circle 300 million kilometers across. (Well, it is actually a giant ellipse but the shape is so close to that

### Earth's Revolution and its Seasons

NAME PER PART 1 - Earth's Revolution: Earth's Revolution and its Seasons Examine the Figure 1 above. Answer these questions. 1. True/False: As Earth revolves around the Sun it is always tilted toward the

### Time, Day, Month, and the Moon

Time, Day, Month, and the Moon Announcements o First Homework will start on Tue Sept 20st; due on Thu, Sept 29th. o Accessible through SPARK Assigned Reading n Units 7 and 8 Goals for Today n To discuss

### The following words and their definitions should be addressed before completion of the reading:

Seasons Vocabulary: The following words and their definitions should be addressed before completion of the reading: sphere any round object that has a surface that is the same distance from its center

### PHSC 3033: Meteorology Seasons

PHSC 3033: Meteorology Seasons Changing Aspect Angle Direct Sunlight is more intense and concentrated. Solar Incidence Angle is Latitude and Time/Date Dependent Daily and Seasonal Variation Zenith There

### Unit 2 - Quiz 2 2-D Models

2-D Models 1. If an observer on Earth views Polaris on the horizon, the observer is located at the A) Tropic of Cancer (23.5 N) B) North Pole (90 N) C) equator (0 ) D) Tropic of Capricorn (23.5 S) 2. At

### Astron 100 Sample Exam 1 1. Solar eclipses occur only at (A) New moon (B) 1 st quarter moon (C) Full moon (D) 3 rd quarter moon (E) The equinoxes 2.

Astron 100 Sample Exam 1 1. Solar eclipses occur only at (A) New moon (B) 1 st quarter moon (C) Full moon (D) 3 rd quarter moon (E) The equinoxes 2. If the Moon is at first quarter tonight in Amherst,

### Lesson 1: Phases of the Moon

Lesson 1: Phases of the Moon The moon takes 29.5 days to revolve around the earth. During this time, the moon you see in the sky appears to change shape. These apparent changes, which are called phases,

### Aim: Latitude and Longitude: The Earth s Coordinate System. Earth Science: Measuring Earth

Aim: Latitude and Longitude: The Earth s Coordinate System Earth Science: Measuring Earth Learning Objective By the end of today s class students should be able to determine and measure latitude and longitude.

### The Analemma for Latitudinally-Challenged People

The Analemma for Latitudinally-Challenged People Helmer ASLAKSEN Shin Yeow TEO Department of Mathematics National University of Singapore Singapore 117543 Singapore Contents Chapter 1 Chapter 2 Introduction.....

### FIRST GRADE 1 WEEK LESSON PLANS AND ACTIVITIES

FIRST GRADE 1 WEEK LESSON PLANS AND ACTIVITIES UNIVERSE CYCLE OVERVIEW OF FIRST GRADE UNIVERSE WEEK 1. PRE: Describing the Universe. LAB: Comparing and contrasting bodies that reflect light. POST: Exploring

### Seasons ASTR 103 9/19/2016

Seasons ASTR 103 9/19/2016 1 What causes the seasons? Perihelion: closest to Sun Around Janury 4 th Northern Summer Southern Winter 147 million km 152 million km Aphelion (farthest to Sun) around July

### Name Homeroom. Science Quiz Day/Night, Sun s Energy, Seasons September 24, 2012

Name Homeroom Science Quiz Day/Night, Sun s Energy, Seasons September 24, 2012 1. The winter solstice occurs on either December 21 or 22, depending on the year. Which of the following statements best explains

### Full credit for this chapter to Prof. Leonard Bachman of the University of Houston

Chapter 6: SOLAR GEOMETRY Full credit for this chapter to Prof. Leonard Bachman of the University of Houston SOLAR GEOMETRY AS A DETERMINING FACTOR OF HEAT GAIN, SHADING AND THE POTENTIAL OF DAYLIGHT PENETRATION...

### Laboratory 4 - Observing the Planets in the Night Sky

Laboratory 4 - Observing the Planets in the Night Sky Materials Used: Star and Planet locator, Star Charts, Cartes du Ciel software. Objectives: To investigate the night sky as it will appear this evening

### Reason for the Seasons Notes

Reason for the Seasons Notes Seasons Vocabulary Seasons - Due to the tilt of earth as it travels around the Sun, we have spring, summer, fall, and winter. Source: http://www.srh.noaa.gov/abq/features/whatcausestheseasons/summersolstice2008.php

### Lab Activity on the Causes of the Seasons

Lab Activity on the Causes of the Seasons 2002 Ann Bykerk-Kauffman, Dept. of Geological and Environmental Sciences, California State University, Chico * Objectives When you have completed this lab you

### CELESTIAL MOTIONS. In Charlottesville we see Polaris 38 0 above the Northern horizon. Earth. Starry Vault

CELESTIAL MOTIONS Stars appear to move counterclockwise on the surface of a huge sphere the Starry Vault, in their daily motions about Earth Polaris remains stationary. In Charlottesville we see Polaris

### The Analemma for Latitudinally-Challenged People

The Analemma for Latitudinally-Challenged People Teo Shin Yeow An academic exercise presented in partial fulfillment for the degree of Bachelor of Science with Honours in Mathematics Supervisor : Associate

### Today. Solstices & Equinoxes Precession Phases of the Moon Eclipses. Ancient Astronomy. Lunar, Solar FIRST HOMEWORK DUE NEXT TIME

Today Solstices & Equinoxes Precession Phases of the Moon Eclipses Lunar, Solar Ancient Astronomy FIRST HOMEWORK DUE NEXT TIME The Reason for Seasons Hypothesis check: How would seasons in the northern

### Motions of Earth, Moon, and Sun

Motions of Earth, Moon, and Sun Apparent Motions of Celestial Objects An apparent motion is a motion that an object appears to make. Apparent motions can be real or illusions. When you see a person spinning

### Celestial Coordinate Systems. HAS Novice Presentation Feb 3, 2009 Justin McCollum

Celestial Coordinate Systems HAS Novice Presentation Feb 3, 2009 Justin McCollum Five Common or Established Coordinate Systems in Use: Horizontal (Altitude & Azimuth) Equatorial (Declination & Right Ascension

### The Four Seasons. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise. The Moon s Phases

The Four Seasons A Warm Up Exercise What fraction of the Moon s surface is illuminated by the Sun (except during a lunar eclipse)? a) Between zero and one-half b) The whole surface c) Always half d) Depends

### Astronomy 1140 Quiz 1 Review

Astronomy 1140 Quiz 1 Review Prof. Pradhan September 15, 2015 What is Science? 1. Explain the difference between astronomy and astrology. (a) Astrology: nonscience using zodiac sign to predict the future/personality

### Noon Sun Angle = 90 Zenith Angle

Noon Sun Angle Worksheet Name Name Date Subsolar Point (Latitude where the sun is overhead at noon) Equinox March 22 nd 0 o Equinox September 22 nd 0 o Solstice June 22 nd 23.5 N Solstice December 22 nd

### Types of Maps. physical map. political map. thematic map. contour map. 3-Part Cards with Definitions

Types of Maps 3-Part Cards with Definitions physical map political map contour map thematic map physical map political map A physical map shows an area's natural A political map shows boundaries of features

### LAB 2 EARTH AND THE SEASONS. Due: Fri Oct :00 PM EDT Question 1. Instructions Lab 2: Earth and the Seasons (Globe Version)

Lab G: Earth and the Seasons (T) (5079) Due: Fri Oct 10 01 1:00 PM EDT Question 1 Instructions Lab : Earth and the Seasons (Globe Version) Read the lab before attending lab. You might find it easier to

### Exercise 5.0 LUNAR MOTION, ELONGATION, AND PHASES

Exercise 5.0 LUNAR MOTION, ELONGATION, AND PHASES I. Introduction The Moon's revolution in orbit around the center of gravity (barycenter) of the Earth- Moon System results in an apparent motion of the

### Lab Module 1: The Observing Project

Lab Module 1 The Observing Project The Location and Time of Sunset OR Fremont Peak Observatory (Worth 15 points) Due Date: The last lab class before finals I. The Location and Time of Sunset Background

### Observations and the Telescope, Laboratory 1

Observations and the Telescope, Laboratory 1 The Great Orion Nebula (M42), picture taken in Dandridge, TN Telescopes come in an enormous number of varieties. Shapes include radio dishes and wires, familiar

### ASTRONOMY 161. Introduction to Solar System Astronomy

ASTRONOMY 161 Introduction to Solar System Astronomy Seasons & Calendars Monday, January 8 Season & Calendars: Key Concepts (1) The cause of the seasons is the tilt of the Earth s rotation axis relative

### Seasons (Observable Patterns)

Seasons (Observable Patterns) E Q U I T A B L E S C I E N C E C U R R I C U L U M Lesson 3 i N T E G R A T I N G A R T S i n P U B L I C E D U C A T I O N NGSS Science Standard: 5-ESS1-2 Represent data

### The ecliptic - Earth s orbital plane

The ecliptic - Earth s orbital plane The line of nodes descending node The Moon s orbital plane Moon s orbit inclination 5.45º ascending node celestial declination Zero longitude in the ecliptic The orbit

### Exploring Solar Energy Variations on Earth: Changes in the Length of Day and Solar Insolation Through the Year

Exploring Solar Energy Variations on Earth: Changes in the Length of Day and Solar Insolation Through the Year Purpose To help students understand how solar radiation varies (duration and intensity) during

### An Introduction to Astronomy and Cosmology. 1) Astronomy - an Observational Science

An Introduction to Astronomy and Cosmology 1) Astronomy - an Observational Science Why study Astronomy 1 A fascinating subject in its own right. The origin and Evolution of the universe The Big Bang formation

### Astrock, t he A stronomical Clock

Astrock, t he A stronomical Clock The astronomical clock is unlike any other clock. At first glance you ll find it has similar functions of a standard clock, however the astronomical clock can offer much

### ASTRONOMY REVIEW Qs (2) (3) (4)

1. Which statement provides evidence that Earth revolves around the Sun? (1) Winds at different latitudes are curved different amounts by the Coriolis effect. (2) Different star constellations are visible

### Astromechanics. 1 solar day = 1.002737909350795 sidereal days

Astromechanics 13. Time Considerations- Local Sidereal Time The time that is used by most people is that called the mean solar time. It is based on the idea that if the Earth revolved around the Sun at

### Finding Stars and Constellations Earth & Sky

Finding Stars and Constellations Earth & Sky Name: Introduction If you carefully watched the night sky over a period of time, you would notice that it s not always the same. There are certain changes that

### Renewable Energy. Solar Power. Courseware Sample 86352-F0

Renewable Energy Solar Power Courseware Sample 86352-F0 A RENEWABLE ENERGY SOLAR POWER Courseware Sample by the staff of Lab-Volt Ltd. Copyright 2009 Lab-Volt Ltd. All rights reserved. No part of this