# There are great circles of longitude which pass through the N and S poles, and which are perpendicular to the equator

Save this PDF as:

Size: px
Start display at page:

Download "There are great circles of longitude which pass through the N and S poles, and which are perpendicular to the equator"

## Transcription

1 The Celestial Globe Astronomers view the sky (half-hemisphere) available to us above the horizon at any time, and from a particular location on the earth. In order to understand where a specific object (e.g. star, planet or galaxy) is, we need a coordinate system attached to the sky, that emulates the longitude, latitude system on the earth. The Earth Coordinate System Let us review that system on the surface of the earth. There are great circles of longitude which pass through the N and S poles, and which are perpendicular to the equator Those great circles define time zones Rochester is close to 75 o W of Greenwich, England or 15h W of Greenwich England. Evidently 24h = 360 o, or 1h = 15 o. Longitude is measured along the Earth s equator to the great circle of longitude through the city of interest, measured from the zero-point, Greenwich. There are parallels of latitude parallel to the equator, and measured in degrees ( o ) N and S of the equator. Note from the figure that they really are parallel, while the longitude circles are not. A great circle means that the associated plane passes through the center of the earth, but the plane associated with the latitude parallels do not. All longitude

2 circles have the same diameter; the latitude circles do not. A quick aside: you might like a very interesting book, Longitude : The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time by Dava Sobel The thorniest scientific problem of the eighteenth century was how to determine longitude. Many thousands of lives had been lost at sea over the centuries due to the inability to determine an east-west position. This is the engrossing story of the clockmaker, John "Longitude" Harrison, who solved the problem that Newton and Galileo had failed to conquer, yet claimed only half the promised rich reward. Coordinate System on the Sky We imagine a similar situation on the sky. The celestial sphere is an imaginary sphere of infinite radius with the earth located at its center. The north and south celestial poles of the celestial sphere are aligned with the N and S poles of the Earth. The celestial equator lies in the same plane as does the Earth's equator. An astronomer can only see half the sky at a time, that is, only half the sky is above the horizon at any time. But the sky keeps moving as the earth rotates. Just as the sun rises and sets every day, so does every star in the sky each night. North Celestial Pole (NCP) and the South Celestial Pole (SCP) - these are just the intersection of the north and south pole axis with the celestial sphere. Celestial Equator Extension of the earth's equatorial plane to its intersection with the celestial sphere Horizon - The horizon changes relative to the polar axis depending on your position on earth. It divides the hemisphere that is the sky from the rest of the celestial sphere. The great circle through the zenith and the NCP intersects the horizon at the cardinal direction on the earth, N. Zenith - The point on the celestial sphere directly overhead and 90 o away from the horizon. Meridian - The line that extends from the north point on the horizon upwards through the zenith and then downward to the south point on the horizon.

3 We can locate any object on the celestial sphere by giving it two coordinates, called the Right Ascension α (analogous to longitude on the Earth) and the Declination δ (analogous to latitude on the Earth). These are called celestial coordinates. Similar to longitude on Earth, the Right Ascension α of an object on the celestial sphere is measured eastward along the celestial equator, from a zero-point (i.e. where α = 0 o ), defined to be the vernal equinox the place where the Sun is on the sky on March 21. Similar to the latitude on Earth, the Declination δ of an object on the celestial sphere is measured northward or southward from the plane containing the equator. δ of the equator is 0 o, δ of the North Celestial Pole NCP, +90 o, and δ of the South Celestial Pole SCP, -90 o.

4 Stars and galaxies have (almost) fixed positions in α and δ. The Sun and planets, on the other hand, move among the distant stars so that their coordinates change throughout the year. Because of the Earth's yearly orbital motion, the Sun appears to circle the ecliptic, inclined at 23.5 o to the celestial equator. All solar system planets and moons are approximately in the ecliptic plane. The comets, however, and their close cousins the Kuiper Belt Objects are more broadly distributed. Latitude and Longitude System on the Earth In addition to the fixed celestial coordinate systems on the sky, based on the earth s coordinates, there are also ALT-AZ horizon-based coordinate systems. The problem is, as the sky apparently turns with time, the altitude ALT and the azimuth AZ change. However, if one knows the sidereal time ST star time (not solar time), it is possible to find the fixed sky coordinates. The altitude ALT is measured in degrees from the horizon.

5 The azimuth AZ is measured from the N point on the horizon with zero degrees corresponding to North, and increasing in a clockwise fashion. Thus, 90 degrees is East, 180 degrees is South, and 270 degrees is West. Sidereal Time and Hour Angle Sidereal Time ST is = the right ascension α of a star on the meridian. Thus ST = 0h when the vernal equinox γ (position of Sun on March 21) is on the meridian. So ST = 0h at noon on March 21, and 12h at noon on September 21. Hour angle HA is the angular measure in h,m,s from the meridian westward along the celestial equator to the foot of the hour circle (like longitude circle) through the object. ST = HA + α In class and in lab you will have many opportunities to exercise these definitions. They are important so that we can go to the telescope and begin observations. Calculators on the web allow you to figure out sidereal time as well as other things. (working as of 2016!) Sidereal Time and Solar Time Careful observation of the sky will show that any specific star will cross directly overhead (on the meridian) about four minutes earlier every day. In other words, the day according to the stars (the sidereal day) is about four minutes shorter than the day according to the sun (the solar day). If we measure a day from noon to noon - from when the sun crosses the meridian (directly overhead) to when the sun crosses the meridian again - we will find the average solar day is about 24 hours. If we measure the day according to a particular star - from when that star crosses the meridian to when that star crosses the meridian again - we will find the average sidereal day is 23 hours and 56 minutes. Referring to our previous assertion that ST = 0 on March 21 at noon, ST will be approximately 0h 4m on March 22, 0h 8m on March 23, and 2h on April 21 at noon.

6 The reason for this is illustrated below. On the first day, point A points directly toward the sun at exactly twelve noon. After a full rotation of the Earth, point A is pointing in the same direction in space, but since the Earth has also proceeded along its orbit, point A is no longer facing the sun. It takes another 4 minutes of rotation for point A to again face the Sun. (The effect is exaggerated in the figure). And over the course of a year s time, the sidereal year is 1 day shorter than a solar year -- [4m/d / (24 x 60m/d)] x 365d/y = 1d/y. So while it is tricky, it is possible to compute the ST fairly readily.

### 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

### 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

### 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

### 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 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

### 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

### 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

### 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

### 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

### 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?

### 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

### 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

### 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

### 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.)

### 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

### 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

### 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

### 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

### 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

### AST101: Our Corner of the Universe Lab 2: The Sun and Phases of The Moon

AST101: Our Corner of the Universe Lab 2: The Sun and Phases of The Moon Name: NetID (your SU email address, without the @syr.edu): Lab section number: 1 Introduction Objectives The first part of this

### 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

### 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

### 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

### 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

### 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

### 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

### 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,

### 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.

### 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

### 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:

### 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

### Latitude and Longitudes in Geodesy James R. Clynch February 2006

Latitude and Longitudes in Geodesy James R. Clynch February 2006 I. Latitude and Longitude on Spherical Earth Latitude and longitude are the grid lines you see on globes. For a spherical earth these are

### 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

### 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

### 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

### Earth In Space Chapter 3

Earth In Space Chapter 3 Shape of the Earth Ancient Greeks Earth casts a circular shadow on the moon during a lunar eclipse Shape of the Earth Ancient Greeks Ships were observed to disappear below the

### 6. The greatest atmospheric pressure occurs in the 1) troposphere 3) mesosphere 2) stratosphere 4) thermosphere

1. The best evidence of the Earth's nearly spherical shape is obtained through telescopic observations of other planets photographs of the Earth from an orbiting satellite observations of the Sun's altitude

### 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

### 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

### Astronomy. Introduction. Key concepts of astronomy. Earth. Day and night. The changing year

Astronomy Introduction This topic explores the key concepts of astronomy as they relate to: the celestial coordinate system the appearance of the sky the calendar and time the solar system and beyond space

### www.mhhe.com/fix Sunrise from Earth orbit by the crew of the STS-47 Space Shuttle Mission. I pray the gods to quit me of my toils,

Confirming Proofs I pray the gods to quit me of my toils, To close the watch I keep this livelong year; For as a watch-dog lying, not at rest, Propped on one arm, upon the palace roof Of Atreus race, too

### 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

### 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

### 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

### 5- Minute Refresher: Daily Observable Patterns in the Sky

5- Minute Refresher: Daily Observable Patterns in the Sky Key Ideas Daily Observable Patterns in the Sky include the occurrence of day and night, the appearance of the moon, the location of shadows and

### 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

### The heavens declare the glory of God; and the firmament sheweth his handywork. Psalm 19:1

The heavens declare the glory of God; and the firmament sheweth his handywork. Psalm 19:1 First printing: April 2012 Copyright 2012 by Jason Lisle. All rights reserved. No part of this book may be used

### astronomy 2008 1. A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times.

1. A planet was viewed from Earth for several hours. The diagrams below represent the appearance of the planet at four different times. 5. If the distance between the Earth and the Sun were increased,

### 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

### The Earth Really is Flat! The Globe and Coordinate Systems. Long History of Mapping. The Earth is Flat. Long History of Mapping

The Earth Really is Flat! The Globe and Coordinate Systems Intro to Mapping & GIS The Earth is Flat Day to day, we live life in a flat world sun rises in east, sets in west sky is above, ground is below

### lat/long/size&shape of Earth 1. Which statement provides the best evidence that Earth has a nearly spherical shape?

Name: Tuesday, September 23, 2008 lat/long/size&shape of Earth 1. Which statement provides the best evidence that Earth has a nearly spherical shape? 1. The Sun has a spherical shape. 3. Star trails photographed

### Motions of Earth LEARNING GOALS

2 Patterns in the Sky Motions of Earth The stars first found a special place in legend and mythology as the realm of gods and goddesses, holding sway over the lives of humankind. From these legends and

### Basic principles of celestial navigation

Basic principles of celestial navigation James A. Van Allen a) Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242 Received 16 January 2004; accepted 10 June 2004 Celestial

### The Size & Shape of the Galaxy

name The Size & Shape of the Galaxy The whole lab consists of plotting two graphs. What s the catch? Aha visualizing and understanding what you have plotted of course! Form the Earth Science Picture of

### 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

### Exam # 1 Thu 10/06/2010 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti

Exam # 1 Thu 10/06/2010 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti INSTRUCTIONS: Please, use the `bubble sheet and a pencil # 2 to answer the exam questions, by marking

### 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

### Proffessor: J. C. Cersosimo

Proffessor: J. C. Cersosimo Objectives Student will: Recognize the Solar and Lunar calendar Demonstrate the how the Moon phases form Explain the main elements of an orbits Describe the orbit of the Earth

### Orion Atlas. EQ Mount INSTRUCTION MANUAL #9830. Customer Support (800) 676-1343 E-mail: support@telescope.com. IN 177 Rev. A 11/02

INSTRUCTION MANUAL Orion Atlas EQ Mount #9830 Providing Exceptional Consumer Optical Products Since 1975 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 P.O.

### Solar System. 1. The diagram below represents a simple geocentric model. Which object is represented by the letter X?

Solar System 1. The diagram below represents a simple geocentric model. Which object is represented by the letter X? A) Earth B) Sun C) Moon D) Polaris 2. Which object orbits Earth in both the Earth-centered

### Lunar Phase Simulator Student Guide

Name: Lunar Phase Simulator Student Guide Part I: Background Material Answer the following questions after reviewing the background pages for the simulator. Page 1 Introduction to Moon Phases Is there

### Determining Polar Axis Alignment Accuracy

Determining Polar Axis Alignment Accuracy by Frank Barrett 7/6/008 Abstract: In order to photograph dim celestial objects, long exposures on the order of minutes or hours are required. To perform this

### Use WITH Investigation 4, Part 2, Step 2

INVESTIGATION 4 : The Sundial Project Use WITH Investigation 4, Part 2, Step 2 EALR 4: Earth and Space Science Big Idea: Earth in Space (ES1) Projects: Tether Ball Pole Sundial Globe and a Light Indoors

### Observing the Constellations of the Zodiac

Observing the Constellations of the Zodiac Activity UCIObs 3 Grade Level: 8 12 Source: Copyright (2009) by Tammy Smecker Hane. Contact tsmecker@uci.edu with any questions. Standards:This activity addresses

### Page. ASTRONOMICAL OBJECTS (Page 4).

Star: ASTRONOMICAL OBJECTS ( 4). Ball of gas that generates energy by nuclear fusion in its includes white dwarfs, protostars, neutron stars. Planet: Object (solid or gaseous) that orbits a star. Radius

### Periods of Western Astronomy. Chapter 1. Prehistoric Astronomy. Prehistoric Astronomy. The Celestial Sphere. Stonehenge. History of Astronomy

Periods of Western Astronomy Chapter 1 History of Astronomy Western astronomy divides into 4 periods Prehistoric (before 500 B.C.) Cyclical motions of Sun, Moon and stars observed Keeping time and determining

### The Mathematics of the Longitude

The Mathematics of the Longitude Wong Lee Nah An academic exercise presented in partial fulfilment for the degree of Bachelor of Science with Honours in Mathematics. Supervisor : Associate Professor Helmer

### 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

APPENDIX D: SOLAR RADIATION The sun is the source of most energy on the earth and is a primary factor in determining the thermal environment of a locality. It is important for engineers to have a working

### Precise Polar Alignment (Drift Alignment)

Precise Polar Alignment (Drift Alignment) OCA AstroImagers Boot Camp March 23, 2006 Dick Greenwald 1 Overview Basics Definition Why drift align? Basic polar alignment methods Error sources Precise polar

### EARTH'S MOTIONS. 2. The Coriolis effect is a result of Earth's A tilted axis B orbital shape C revolution D rotation

EARTH'S MOTIONS 1. Which hot spot location on Earth's surface usually receives the greatest intensity of insolation on June 21? A Iceland B Hawaii C Easter Island D Yellowstone 2. The Coriolis effect is

### Activity 10 - Universal Time

Activity 10 - Universal Time Teacher s Guide Scientists use the Universal Time reference to talk about data that is taken around the globe. Universal Time is the time kept in the time zone centered on

### Measuring Your Latitude from the Angle of the Sun at Noon

Measuring Your Latitude from the Angle of the Sun at Noon Background: You can measure your latitude in earth's northern hemisphere by finding out the altitude of the celestial equator from the southern

### Sunlight and its Properties. EE 495/695 Y. Baghzouz

Sunlight and its Properties EE 495/695 Y. Baghzouz The sun is a hot sphere of gas whose internal temperatures reach over 20 million deg. K. Nuclear fusion reaction at the sun's core converts hydrogen to

### New star gazers often believe the North Star (Polaris) is brightest of all, even mistaking

Reprinted From AAC Newsletter FirstLight (2010 May/June) Chasing the Pole Howard L. Cohen Polaris like supernal beacon burns, a pivot-gem amid our star-lit Dome ~ Charles Never Holmes (1916) New star gazers

### Note S1: Eclipses & Predictions

The Moon's Orbit The first part of this note gives reference information and definitions about eclipses [14], much of which would have been familiar to ancient Greek astronomers, though not necessarily

### Geography I Pre Test #1

Geography I Pre Test #1 1. The sun is a star in the galaxy. a) Orion b) Milky Way c) Proxima Centauri d) Alpha Centauri e) Betelgeuse 2. The response to earth's rotation is a) an equatorial bulge b) polar

### 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...

### GOTOSTAR HAND CONTROLLER AND DUAL-AXIS DC SERVO-MOTOR DRIVER

GOTOSTAR HAND CONTROLLER AND DUAL-AXIS DC SERVO-MOTOR DRIVER The new GOTOSTAR hand controller and our specially designed dual-axis DC servomotor driver is our new patent product. The controlling accuracy

### 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

### COASTLINING THE ZODIAC

COASTLINING THE ZODIAC Astronomy books and skywatching guides offer a wide variety of charts for naked-eye observation of the skies. What works best for each person will depend on various factors such

### Stellar, solar, and lunar demonstrators

Stellar, solar, and lunar demonstrators Rosa M. Ros, Francis Berthomieu International Astronomical Union, Technical University of Catalonia (Barcelona, España), CLEA (Nice, France) Summary This worksheet

### Assignment 2. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

Assignment 2 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. What would you have to change about the Earth to stop our planet from having

### Local Sidereal Time is the hour angle of the First Point of Aries, and is equal to the hour angle plus right ascension of any star.

1 CHAPTER 7 TIME In this chapter we briefly discuss the several time scales that are in use in astronomy, such as Universal Time, Mean Solar Time, Ephemeris Time, Terrestrial Dynamical Time, and the several

### Motions of the Earth. Stuff everyone should know

Motions of the Earth Stuff everyone should know Earth Motions E W N W Noon E Why is there day and night? OR Why do the Sun and stars appear to move through the sky? Because the Earth rotates around its

### 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

### Section 3 Mapping Earth s Surface

Section 3 Mapping Earth s Surface Key Concept Maps are tools that are used to display data about a given area of a physical body. What You Will Learn Maps can be used to find locations on Earth and to

### The Revolution of the Moons of Jupiter Student Manual

The Revolution of the Moons of Jupiter Student Manual A Manual to Accompany Software for the Introductory Astronomy Lab Exercise Document SM 1: Circ.Version 1.1.1 Department of Physics Gettysburg College

### Chapter 5 Astronomy 110 Motions of the Sun and the Moon 1

Chapter 5 Positions of the Sun and Moon Objects in our Solar System appear to move over the course of weeks to months because they are so close. This motion caused ancient astronomers to use the name planets,

### 1. In the diagram below, the direct rays of the Sun are striking the Earth's surface at 23 º N. What is the date shown in the diagram?

1. In the diagram below, the direct rays of the Sun are striking the Earth's surface at 23 º N. What is the date shown in the diagram? 5. During how many days of a calendar year is the Sun directly overhead

### SkyView Pro EQ Mount. instruction Manual #9829. Customer Support (800) 676-1343 IN 195 Rev. B 03/09

instruction Manual Orion SkyView Pro EQ Mount #9829 Providing Exceptional Consumer Optical Products Since 1975 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000

### An Introduction to Coordinate Systems in South Africa

An Introduction to Coordinate Systems in South Africa Centuries ago people believed that the earth was flat and notwithstanding that if this had been true it would have produced serious problems for mariners

Project ATMOSPHERE This guide is one of a series produced by Project ATMOSPHERE, an initiative of the American Meteorological Society. Project ATMOSPHERE has created and trained a network of resource agents

### Week 1-2: Overview of the Universe & the View from the Earth

Week 1-2: Overview of the Universe & the View from the Earth Hassen M. Yesuf (hyesuf@ucsc.edu) September 29, 2011 1 Lecture summary Protein molecules, the building blocks of a living organism, are made

### CHAPTER 3. The sun and the seasons. Locating the position of the sun

zenith 90 summer solstice 75 equinox 52 winter solstice 29 altitude angles observer Figure 3.1: Solar noon altitude angles for Melbourne SOUTH winter midday shadow WEST summer midday shadow summer EAST

### Lines of Latitude and Longitude

ED 5661 Mathematics & Navigation Teacher Institute Keith Johnson Lesson Plan Lines of Latitude and Longitude Lesson Overview: This lesson plan will introduce students to latitude and longitude along with

### 2. Orbits. FER-Zagreb, Satellite communication systems 2011/12

2. Orbits Topics Orbit types Kepler and Newton laws Coverage area Influence of Earth 1 Orbit types According to inclination angle Equatorial Polar Inclinational orbit According to shape Circular orbit