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Computer Program Detail Page

Item Picture
Solar and Lunar Eclipse JS Model
written by Wolfgang Christian, Todd Timberlake, and Mario Belloni
The Solar and Lunar Eclipse JavaScript Model simulates the occurrences of solar and lunar eclipses. Moon's orbital inclination of 5.145 degrees with respect to the ecliptic (the Earth-Sun orbital plane) is what is responsible for solar and lunar eclipses not occurring every month. In addition, the orbital plane of Moon precesses every 8.85 years, the so-called precession of the apsides. The inclination and the motion of Moon and Earth are depicted (the size of Sun, Earth, and Moon and the size of Moon's orbit are not shown to scale). The illuminated sides of Earth and Moon and the regions of possible eclipses (in yellow and green) are also depicted. In the Sky View, the motion of Sun and Moon across the sky (+/- 7 degrees from the ecliptic) are shown. Moon's phase is shown and solar and lunar eclipses can occur on the ecliptic when Earth, Sun, and Moon line up properly.  

The Solar and Lunar Eclipse JavaScript Model was developed using the Easy Java/JavaScript Simulations (EJS) modeling tool. Although EJS is a Java program, EJS v5 and above can be used to create stand-alone JavaScript programs that run in almost any browser.
1 supplemental document is available
1 source code document is available
Subjects Levels Resource Types
- Astronomy Education
= Curricula
- Fundamentals
= Eclipses
= Lunar Phases
- Solar System
= The Moon
- Lower Undergraduate
- Middle School
- High School
- Informal Education
- Instructional Material
= Interactive Simulation
Intended Users Formats Ratings
- Educators
- Learners
- application/javascript
- text/html
- application/zip
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Access Rights:
Free access
This material is released under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 license.
Rights Holder:
Wolfgang Christian
ecliptic plane, lunar eclipse, solar eclipse
Record Cloner:
Metadata instance created May 13, 2017 by Wolfgang Christian
Record Updated:
September 21, 2021 by Lyle Barbato
Last Update
when Cataloged:
May 13, 2017
Other Collections:

Next Generation Science Standards

Disciplinary Core Ideas (K-12)

Earth and the Solar System (ESS1.B)
  • This model of the solar system can explain eclipses of the sun and the moon. Earth's spin axis is fixed in direction over the short-term but tilted relative to its orbit around the sun. The seasons are a result of that tilt and are caused by the differential intensity of sunlight on different areas of Earth across the year. (6-8)
  • Kepler's laws describe common features of the motions of orbiting objects, including their elliptical paths around the sun. Orbits may change due to the gravitational effects from, or collisions with, other objects in the solar system. (9-12)

Crosscutting Concepts (K-12)

Systems and System Models (K-12)
  • When investigating or describing a system, the boundaries and initial conditions of the system need to be defined and their inputs and outputs analyzed and described using models. (9-12)
  • Models can be used to predict the behavior of a system, but these predictions have limited precision and reliability due to the assumptions and approximations inherent in models. (9-12)

NGSS Science and Engineering Practices (K-12)

Developing and Using Models (K-12)
  • Modeling in 9–12 builds on K–8 and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds. (9-12)
    • Use a model to predict the relationships between systems or between components of a system. (9-12)
ComPADRE is beta testing Citation Styles!

Record Link
AIP Format
W. Christian, T. Timberlake, and M. Belloni, Computer Program SOLAR AND LUNAR ECLIPSE JS MODEL, Version 1.0 (2017), WWW Document, (
W. Christian, T. Timberlake, and M. Belloni, Computer Program SOLAR AND LUNAR ECLIPSE JS MODEL, Version 1.0 (2017), <>.
APA Format
Christian, W., Timberlake, T., & Belloni, M. (2017). Solar and Lunar Eclipse JS Model (Version 1.0) [Computer software]. Retrieved July 15, 2024, from
Chicago Format
Christian, W, T. Timberlake, and M. Belloni. "Solar and Lunar Eclipse JS Model." Version 1.0. (accessed 15 July 2024).
MLA Format
Christian, Wolfgang, Todd Timberlake, and Mario Belloni. Solar and Lunar Eclipse JS Model. Vers. 1.0. Computer software. 2017. 15 July 2024 <>.
BibTeX Export Format
@misc{ Author = "Wolfgang Christian and Todd Timberlake and Mario Belloni", Title = {Solar and Lunar Eclipse JS Model}, Month = {May}, Year = {2017} }
Refer Export Format

%A Wolfgang Christian %A Todd Timberlake %A Mario Belloni %T Solar and Lunar Eclipse JS Model %D May 13, 2017 %U %O 1.0 %O text/html

EndNote Export Format

%0 Computer Program %A Christian, Wolfgang %A Timberlake, Todd %A Belloni, Mario %D May 13, 2017 %T Solar and Lunar Eclipse JS Model %7 1.0 %8 May 13, 2017 %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.

Solar and Lunar Eclipse JS Model:

Is Based On Easy Java Simulations Modeling and Authoring Tool

Use the Easy Java Simulations Modeling and Authoring Tool to edit and to explore the source code for the Solar and Lunar Eclipse JS Model.

relation by Wolfgang Christian

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