Posted: April 25th, 2025

Lunar Phase Project

Find sunrise and moon rise times for 10/3/2024 through 11/3/2024 – https://www.timeanddate.com/moon/usa/modesto

Lunar Phase description video Link- https://mccd.us-west-2.instructuremedia.com/embed/28f93432-f06c-47c8-a211-b565492f3102

Astronomy project

Lunar Phases

1-
Introduction

The lunar phase project involves observing the phase of the moon every day over a complete lunar cycle. For this project the observing location can change each day, but you must note it down in your observation section. Also, note that the time at which the moon will be visible will change during the cycle. Sometimes the moon will be visible during the day, and sometimes it will be visible at night. On occasion you may have to stay up late or wake up early in order to make an observation.

You should sketch an image of the phase of the moon in your log, and include the local sunrise and moonrise time that day. You can obtain the sunrise and moonrise time for any day by using the

website

. (

https://www.timeanddate.com/moon

). You may choose your living zip code.

From the sunrise and moonrise time you can calculate the angular separation of the sun and the moon. Figure out how many hours and minutes pass between sunrise and the next moonrise. The earth rotates on its axis about 360 degrees in 24 hours, which means it rotates 15 degree every hour or 0.25 degrees every minute. You can convert the time separation between sunrise and moonrise into an approximate angular separation between the sun and the moon by multiplying each hour by 15 degree and each minute 0.25 degree. As an example, if the moon rises 3 hours and 12 minute after the sun, then the angular separation is 3*15+ 12*0.25 = 48 degree.

2- Observations.

Record your observations in the table below. Include the date and time you observed the moon, moonrise and sunrise times for the day, and a sketch of the phase of the moon as you see it that day.

Date

Time

Sunrise time

Moonrise time

Sketch of phase

Date

Time

Sunrise time

Moonrise time

Sketch of phase

2-
Calculations

For each observation record in the previous section, calculate the angular separation between the sun and moon using the sunrise and moonrise times and the method discussed in the introduction. Describe the phase you sketched above as an estimate of what percentage of the moon is illuminated.(between 0% and 100%) as well as which side of the moon is illuminated.(left or right).

3-
Analysis

You should see a relation between angular separation and moon phase.Please label the dates when the moon was approximately in each of the 8 positions shown on the circle surrounding the earth below. Note the sun is consistently to the right of the earth in the figure below,well of the page. The arrows represent the direction of the sun’s rays. Draw the phase of the moon for each of the eight positions below.

In the space below explain the phases of the moon in terms of the figure above.

image1.gif