By Michael E. Carpenter, Updated Mar 24, 2022
The Moon orbits Earth every 27.3 days, completing a full revolution and revealing its phases as sunlight illuminates different portions of its surface. Whether you prefer a nightly routine or a single‑night observation, this guide provides clear, step‑by‑step instructions to track the Moon’s movement and understand its phases.
Begin your observations on the day of a New Moon—when the Moon is invisible in the sky. Most lunar calendars or the Time & Date website list New Moon dates.
Select a fixed time each night, ideally at Moonrise, to record the Moon’s position. Use the US Naval Observatory or the Time & Date website to find accurate Moonrise times for your location.
Find an open area with unobstructed views of the eastern and western horizons. A consistent, flat location will help you track the Moon’s east‑to‑west trajectory accurately.
During your observation, draw a quick sketch of the Moon’s appearance. This visual record will help you compare phases and track its movement over the cycle.
Note the Moon’s altitude (height above the horizon) and its relative position across the sky. Use a familiar landmark—such as a nearby building or tree—and measure distance with your hand held at arm’s length. Count how many “hand widths” separate the Moon from the landmark.
Persist with nightly observations until you reach the Full Moon, typically about two weeks after the New Moon. Alternatively, you can continue until the next New Moon, marking a full lunar cycle of roughly 30 days.
Check the Moonrise time for your area using the US Naval Observatory or the Time & Date website.
Position yourself in a room with a window that offers a clear view of both the eastern and western horizons. If a natural window is lacking, a clear plexiglass board can serve as a temporary backdrop.
Place a moon‑shaped marker on the window at the exact moment of Moonrise. This will serve as your reference point.
Every hour, move the marker to the new Moon position, creating a visual trail of its path across the sky.
Keep adding hourly markers until the Moon sets or becomes too faint to see through the window.
By following these systematic steps, you’ll gain a deeper appreciation for the Moon’s dynamic journey across our night sky.
