Lab: Moon Phases
Objective: Determine the relationship between the positions of the Earth, Moon, and Sun over
several observations.
Pre-Lab Questions:
1. What do you expect will happen to the Moon’s appearance over your observation period?
2. How does the location of the Earth, Moon, and Sun at any given time relate to the phase
of the Moon seen?
Procedure:
1. Over the next two weeks, observe the Moon on at least 5 different days.
2. For each observation, make a sketch on the lab sheet showing how the Moon appears
in the sky and label it with the name of the phase.
3. For each observation, record the date and time of day (including am or pm) the
observation was made, as well as the number of days since the previous observation.
4. For each observation, describe approximately where in the sky the Moon is located.
(For example, "low in the sky in the southeast", "on the western horizon", or "high in
the sky towards the south".) Also give a basic description of any features visible on
the Moon and note any changes from previous observations.
5. For each observation, include additional notes that are relevant or of interest (weather
conditions, apparent size on sky, etc.).
6. For each observation, place the Moon on the diagram in the appropriate location and
label it with the date of the observation.
7. Study the sketches, notes, and diagrams you have completed and then answer the
questions at the end of the lab.
