This interactive model simulates solar and lunar eclipses. By viewing the Moon's orbital inclination (5.145 degrees with respect to the ecliptic), students can visualize why solar and lunar eclipses do not happen every month. The model also serves to clarify the process of Moon precession, a change in the orientation of the Moon's rotational axis as it rotates around the Earth. The model does not introduce the geometry of inclination and precession; rather, it aims to provide ways to visualize the processes in either 2D or 3D. 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 Ecliptic 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.
Please note that this resource requires
at least version 1.5 of Java (JRE).
Editor's Note:Note to Teachers: Viewing the model in 3D will require an additional free software download.
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 9â12 builds on Kâ8 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)
Solar and Lunar Eclipse Model Source Code
Source Code for the Solar and Lunar Eclipse Model program. download 296kb .zip
Published: November 13, 2009
Rights: This material is released under the GNU General Public License Version 3.
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 9â12 builds on Kâ8 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)
<a href="https://www.compadre.org/precollege/items/detail.cfm?ID=9640">Belloni, Mario, and Todd Timberlake. "Solar and Lunar Eclipse Model ." Version 1.0.</a>
M. Belloni and T. Timberlake, Computer Program SOLAR AND LUNAR ECLIPSE MODEL , Version 1.0 (2009), WWW Document, (https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407).
M. Belloni and T. Timberlake, Computer Program SOLAR AND LUNAR ECLIPSE MODEL , Version 1.0 (2009), <https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407>.
Belloni, M., & Timberlake, T. (2009). Solar and Lunar Eclipse Model (Version 1.0) [Computer software]. Retrieved March 23, 2025, from https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407
Belloni, Mario, and Todd Timberlake. "Solar and Lunar Eclipse Model ." Version 1.0. https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407 (accessed 23 March 2025).
Belloni, Mario, and Todd Timberlake. Solar and Lunar Eclipse Model . Vers. 1.0. Computer software. 2009. Java (JRE) 1.5. 23 Mar. 2025 <https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407>.
%A Mario Belloni %A Todd Timberlake %T Solar and Lunar Eclipse Model %D November 13, 2009 %U https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407 %O 1.0 %O application/java
%0 Computer Program %A Belloni, Mario %A Timberlake, Todd %D November 13, 2009 %T Solar and Lunar Eclipse Model %7 1.0 %8 November 13, 2009 %U https://www.compadre.org/Repository/document/ServeFile.cfm?ID=9640&DocID=1407
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NGSS Standards (5)
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