A tool to plan an astro-orienteering walk
Would you like to know how the inner planets of the solar system are arranged around the Sun today? Would you like your students to participate in astronomical orienteering walk in the neighbourhood?
Use this tool to determine the positions of the planets in relation to the Sun, and with a suitable scale (1 AU in reality corresponds to 100 m in the model, for example) combine your neighbourhood map with the image showing the current positions of the planets. With a suitable scale you can find a nice position for the Sun and the planets around your school.
The procedure is as follows:
1. Read the instructions below. To complete this task, you will need to download the GeoGebra application. Once you have opened the application, these instructions will no longer be visible. Therefore, print them out so that you can refer to them later.
2. Prepare the map of the region you want to use for your orienteering. You can use the Google application My Maps for this purpose. When you save the map as an image, make sure that a scale is displayed in the lower right corner of the map. (If you enable the Draw Lines and Measure Distances tool, you can draw a longer scale line on the map to increase accuracy.
3. Check the Google Maps Help if you can not find these tools.)
4. Download the GeoGebra application (this one).
5. Find the ephemerides RIGHT ASCENSION and RANGE [AU] of the Sun, Mercury, Venus, and Mars (and Jupiter, if you wish) on a website (there are many that provide this data) and enter the data into the spreadsheet. Right ascension is given in hours [h], minutes [min], and seconds [sec], and ranges from 0 to 24 hours. Declination is given in degrees [deg], minutes [min], and seconds [sec] and can be positive or negative. If the declination is positive, simply enter the [deg], [min], and [sec] of the planets in the appropriate fields on the worksheet. If the declination is negative, enter the minus sign (-) along with the absolute value of [deg] in the appropriate field and write only the absolute values of [min] and [sec] in the other two fields for declination. RANGE of the planets in astronomical units should be written in the last field.
6. Select your scale for the model solar system (1: 1 AU corresponds to 100 m, 2: 1 AU corresponds to 50 m, or 3: 1 AU corresponds to 33.3 m). For example, if you choose scale 1, the Earth is 100 m from the Sun. The coloured dashed lines represent the approximate orbits of the planets (all circles with the radii of the average distance of the planets from the Sun).
7. Delete the sample map image from the applet.
8. Insert an image of the map of your own neighbourhood with a scale that should be visible (in Google Maps you can draw a line like in the example map image with known length - in the example 300 m).
9. Check the Map scaling tool: a fixed point is displayed, the center of the circle with the radius (in [meters]) specified by the button SCALE _{map}.
10. Choose appropriate radius, for example 300 (meters), to match the length of the line drawn in the Google Maps image.
11. Resize the map image to match the scale of the solar system model (you will probably have to move the image first, then resize, move, resize, etc. until they match).
12. Move the map image to match the position of the Sun model you selected.
13. Rotate the solar system model as you wish (so that the planet is not on a roof or in the middle of a busy road).
14. Print(screen) the superposition of the map image and the planets distribution for yourself.