1. Altitude Azimuth 3 rd Coordinate System Your zenith Your zenith 180 degrees from you zenith is Nadir directly on the other side of earth 180 degrees from you zenith is Nadir directly on the other side of earth We can only see the things above our horizon line We can only see the things above our horizon line Anything below our horizon line is denoted as negative altitudes Anything below our horizon line is denoted as negative altitudes We need more than altitude to place a pinpoint a celestial body in our sky We need more than altitude to place a pinpoint a celestial body in our sky We need an Azimuth We need an Azimuth

2. Azimuth Zn We measure in reference to the horizon such as 0 degrees at true north We measure in reference to the horizon such as 0 degrees at true north Runs clockwise up to 360 degrees Runs clockwise up to 360 degrees

3. Altitude Azimuth Uses the altitude in horizontal circles Uses the altitude in horizontal circles –Principal verticle circle (due north and south) Azimuth in vertical circles Azimuth in vertical circles –Each has an upper branch and a lower branch –Prime Vertical Passes through 90 (which would be due east) 270 (which would be due west) Passes through 90 (which would be due east) 270 (which would be due west)

4. Create an Azimuth Zn Sphere 2 paper plates marked with hole at top and bottom, 2 paper plates marked with hole at top and bottom, Cut around from hole to hole, do not cut completely apart. Cut around from hole to hole, do not cut completely apart. Turn and glue. Turn and glue. Mark our 0N, 90E, 180S, and 270W degrees. Mark our 0N, 90E, 180S, and 270W degrees.