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Computer Program Detail Page

Item Picture
Phases of Moon Model
written by Todd Timberlake
The EJS Phases of Moon model displays the appearance of Moon and how it changes depending on the position of Moon relative to Earth and Sun. The main window shows Earth (at the center) and Moon, as well as a circle tracing out Moon's orbit. Sun is far to the right in this picture and therefore the right side of Earth and Moon are bright while the left sides are dark.  By using the Options Menu the Moon View window shows the appearance of Moon as seen from Earth  when Moon is in the position shown in the main window.  You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item.

The EJS Phases of Moon model includes three supplemental documents (see below) that include a middle school lesson plan, a college level worksheet, and the student version of the program.

EJS Phases of Moon model was created using the Easy Java Simulations  (Ejs) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.   Double clicking the ejs_astronomy_MoonPhases.jar file will run the program if  Java is installed.  Ejs is a part of the Open Source Physics Project and is designed  to make it easier to access, modify, and generate computer models.  Additional Ejs  models for astronomy are available.  They can be found by searching ComPADRE for  Open Source Physics, OSP, or Ejs.

Please note that this resource requires at least version 1.5 of Java (JRE).
7 supplemental documents are available
2 source code documents are available
Subjects Levels Resource Types
- Astronomy Education
= Curricula
- Fundamentals
= Lunar Phases
- Solar System
= The Moon
- Lower Undergraduate
- Middle School
- High School
- Instructional Material
= Interactive Simulation
- Audio/Visual
= Image/Image Set
Intended Users Formats Ratings
- Learners
- Educators
- General Publics
- application/java
  • Currently 5.0/5

Rated 5.0 stars by 3 people

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Access Rights:
Free access
© 2009 Todd Timberlake
EJS, Easy Java Simulations, OSP, Open Source Physics, astronomy simulation, lunar, lunar phases, moon, moon phase simulation, phase
Record Creator:
Metadata instance created July 31, 2009 by Mario Belloni
Record Updated:
June 11, 2014 by Andreu Glasmann
Last Update
when Cataloged:
July 31, 2009
Other Collections:


Author: Ahmedelshfie
Posted: March 17, 2011 at 7:26AM
Source: The Open Source Physics collection

Nice applet, thanks  for share.

» reply

Earth sceince resource

Author: Nina Daye
Posted: October 23, 2010 at 3:12PM
Source: The Open Source Physics collection

Wonderful simulation for earth science too!

» reply

the lesson design is fantastic!

Author: lookang
Posted: August 16, 2010 at 10:51PM
Source: The Open Source Physics collection

i especially liked the tennis ball and torchlight to situated the learning to a real world example, a lot of teachers will benefit from this kind of insightful lesson strategy, instead rushing into the powerpoint and talk and talk.

great lesson package!

» reply

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AAAS Benchmark Alignments (2008 Version)

4. The Physical Setting

4A. The Universe
  • K-2: 4A/P2. The sun can be seen only in the daytime, but the moon can be seen sometimes at night and sometimes during the day. The sun, moon, and stars all appear to move slowly across the sky.
  • K-2: 4A/P3. The moon looks a little different every day but looks the same again about every four weeks.
4B. The Earth
  • 6-8: 4B/M5. The moon's orbit around the earth once in about 28 days changes what part of the moon is lighted by the sun and how much of that part can be seen from the earth- the phases of the moon.

11. Common Themes

11B. Models
  • 6-8: 11B/M1. Models are often used to think about processes that happen too slowly, too quickly, or on too small a scale to observe directly. They are also used for processes that are too vast, too complex, or too dangerous to study.

NSES Content Standards

Con.D: Earth & Space Science
  • K-4: Objects in the Sky
  • K-4: Changes in Earth & Sky

NSES Professional Development Standards

PD.A: Learn Science Content through Inquiry
  • Active Investigation: Involve teachers in actively investigating phenomena that can be studied scientifically, interpreting results, and making sense of findings consistent with currently accepted scientific understanding.
ComPADRE is beta testing Citation Styles!

Record Link
AIP Format
T. Timberlake, Computer Program PHASES OF MOON MODEL, Version 1.0 (2009), WWW Document, (
T. Timberlake, Computer Program PHASES OF MOON MODEL, Version 1.0 (2009), <>.
APA Format
Timberlake, T. (2009). Phases of Moon Model (Version 1.0) [Computer software]. Retrieved July 15, 2024, from
Chicago Format
Timberlake, Todd. "Phases of Moon Model." Version 1.0. (accessed 15 July 2024).
MLA Format
Timberlake, Todd. Phases of Moon Model. Vers. 1.0. Computer software. 2009. Java (JRE) 1.5. 15 July 2024 <>.
BibTeX Export Format
@misc{ Author = "Todd Timberlake", Title = {Phases of Moon Model}, Month = {July}, Year = {2009} }
Refer Export Format

%A Todd Timberlake %T Phases of Moon Model %D July 31, 2009 %U %O 1.0 %O application/java

EndNote Export Format

%0 Computer Program %A Timberlake, Todd %D July 31, 2009 %T Phases of Moon Model %7 1.0 %8 July 31, 2009 %U

Disclaimer: ComPADRE offers citation styles as a guide only. We cannot offer interpretations about citations as this is an automated procedure. Please refer to the style manuals in the Citation Source Information area for clarifications.

Citation Source Information

The AIP Style presented is based on information from the AIP Style Manual.

The APA Style presented is based on information from APA Electronic References.

The Chicago Style presented is based on information from Examples of Chicago-Style Documentation.

The MLA Style presented is based on information from the MLA FAQ.

This resource and its subdocuments is stored in 32 shared folders.

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Phases of Moon Model:

Is Based On Easy Java Simulations Modeling and Authoring Tool

The Easy Java Simulations Modeling and Authoring Tool is needed to explore the computational model used in the EJS Phases of the Moon Model.

relation by Mario Belloni

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