Yes, the position of Copernicus. Yes, the control could be the apparent flat, circular surface of the moon facing Earth. The location of Copernicus could be compared to the rim and compass coordinates of this circle. Yes, controlled variables are such things as the time of day each observation is made and the type of measuring tool used to make the angular measurements. V. Data Data is the only way that a judge has to determine whether or not you did an experiment.
Judges like to see tables, charts, or graphs of the measured results.
Any project that has data generally gets an automatic second look by judges. If there is no data, judges start to look for the reason why, and they usually conclude that the student doesn't understand what an experiment is or how to do one. Once you have decided on your project question, your hypothesis, and basically how you are going to test your hypothesis experimentally and record data, then start your project by designing the experiment step by step. Do perform the experiment four or more times. Since time is a factor in this example investigation, you may wish to make four observations as close together as possible each day.