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 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.

Terrestrial Coordinates
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 …show more content…

Experiment with this view until you can quickly create the two views shown below. Note that these images explain the shape of the elliptic on the celestial sphere. In the image on the left (summer solstice) an observer on the Earth sees the sun above the celestial equator. In the image on the right (winter solstice) an observer on the Earth sees the sun below the celestial equator.

Left Panel – Celestial Sphere This view shows the earth at the center of the celestial sphere. The celestial equator and the ecliptic with the sun’s location are shown. Note that you may click on the sun and drag it and read out its coordinates. Experiment with this view until you can quickly create the image to the right – the direct rays of the sun hitting the earth on the summer solstice. Upper Right Panel – View from Sun This view shows the earth as seen from the sun. It gives the best view of the subsolar point – the location on the earth where the direct rays of the sun are hitting. The noon observer’s location on the Earth is indicated by a red parallel of latitude which can be dragged to new latitudes (this affects the appearance of the lower right panel). It is possible for the red parallel to be at an inaccessible location in this view. Create the image shown to the right – an observer at latitude 80°N on the summer solstice.

NAAP – Basic Coordinates & Motions 5/8

Upper Right Panel – View from Side This view shows the