Set the chart mode to local horizon. Set the field to 45°, azimuth of 180°, and altitude to 20°. Lock the display on altitude and azimuth. Turn on the constellation names. Set the geographic location to Santiago, Chile. Set the time step to 15 minutes and start the animation. Note the constellations that are in the southern part of the sky as viewed from Santiago. Now set the geographic location to Tucson, Arizona. Start the animation and note the constellations visible above the southern horizon from Tucson. Switch back and forth from Tucson to Santiago until you are able to identify at least 8 constellations that can be seen from Santiago but not from Tucson. What do your results have to do with the reasons astronomers have built observatories in the southern hemisphere?
