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 seasons on the Earth. Each of these sections has its own simulator(s). The background material necessary to utilize these tools is contained in each section.
Work through the explanatory material on units of longitude and latitude, finding longitude and latitude, and a bit of history (optional). Open the flat map explorer. Familiarize yourself with the cursor and how it prints out the longitude and latitude of the active map location. Note that you can vary the central meridian of the map (i.e. change its longitude). Use the “shift map” arrows at the top of the simulator to affect large rapid changes. Use the shift-click feature of the cursor for finer control. Note what information is accessible through the show cities and show map features check boxes. Center the cursor on your present location. Click the open Google Maps button to launch the Google Map tool focused on this location. Experiment until you get a good feeling for the Google Map’s capabilities and then close this window. (Note that you must be connected to the Internet to make use of this feature.) Question 1: Use the flat map explorer to complete the following table. You are encouraged to try and predict the answers and then use the map’s cursor and other features to check the accuracy of your estimates. Location The center of the island of Madagascar. 157.5º W Prime Meridian 82.1º W Sao Paulo, Brazil International Date Line Arctic Circle 90º W Meridian 30º N Parallel Question 2: Determine which of the 50 states defines the farthest extent of the United States in each of the 4 map directions. NAAP – Basic Coordinates & Motions 1/8 21.2º N 51.8º N Tropic of Cancer Longitude Latitude
Direction North South East (there are two ways of thinking about this) West
Question 3: The exact coordinates of the white house in Washington D.C., are 77.0365º W and 38.897º N. What are these exact coordinates in sexagesimal notation? Show your calculation in the box below. (You can use the Google Map tool to check your answer.)
Open the globe explorer. You are encouraged to use the Terrestrial Coordinate Explorers link which opens both simulators at the same time for the following two questions. Familiarize yourself with the features noting that they are very similar to those in the flat map explorer. Question 4: A) Where is the north pole on the flat map explorer? What is its shape?
B) Where is the north pole on the globe explorer? What is its shape?
C) Your answers to parts A and B should be different. Explain why.
NAAP – Basic Coordinates & Motions 2/8
Question 5: Compare the relative sizes of Greenland and Australia in the two maps? The true values of the surface areas for these countries are Greenland (2.2 million km2) and Australia (7.7 million km2). Does each map demonstrate these true values?
Celestial Equatorial Coordinates
Work through the introductory material on the page entitled Celestial Equator, Declination, Right Ascension. Open either the Flat Sky Map Explorer or the Sky Map Explorer. Familiarize yourself with the same set of features (cursor movement, shifting the map, decimal/sexagesimal) that were available on the previous maps. Make sure that you understand what each check box does. Question 6: Where is the star Polaris located on this map? What are its coordinates?
Question 7: Find the constellation of Orion shown in the box below and measure the right ascension and declination of its brightest stars Betelgeuse and Rigel. Note that Orion is located on the celestial equator.
NAAP – Basic Coordinates & Motions 3/8
Question 8: Which direction is east on the flat sky map? Relate this to a coordinate of the celestial equatorial system.
Question 9: Complete the...