Exploring the Solar System

Your students can learn more about our solar system with these lesson plan ideas.

By Lynsey Peterson

Exploring the Solar System

When I think about our galaxy, one of countless others in the solar system, I feel a sense of awe. Scientists agree that it formed around 4.6 billion years ago when a cloud of gas was compressed and collapsed inward under the force of gravity. When the cloud collapsed, most of its mass and energy was transfered  to the Sun, while some of the remaining debris clumped and began to form planetesimals. These bodies collided and accumulated mass that eventually formed the planets we know today. What remained of the debris became asteroids, comets, and moons.

Identifying the Planets

Evidence for the origins of our solar system can be found in the planets themselves. The inner planets are terrestrial and rocky; composed of heavier atoms that were drawn closer to the center because of the pull of gravity. The outer planets are gaseous and composed of lighter elements such as hydrogen and helium. The boundary between the inner and outer planets, delineated by the asteroid belt, falls between Mars and Jupiter.

Students can remember the order of the planets using a mnemonic. While there are many different ones that you can use, students might like funny ones such as “My Very Excellent Mother Just Served Us Nachos.” I like to have my students create their own. Teaching students to use these types of devices is important and they often remember their own creative sentences better than any of the ones I could provide.

What about Pluto?

Students may wonder about Pluto at this point since it is no longer defined as a planet. Of course, subsequent generations may not even remember that we considered this icy body our ninth planet. A discussion of Pluto provides a good opportunity to illustrate how scientific categories can change due to new information.

In 2005, astronomers found evidence of Eris, an object orbiting the Sun that is larger than Pluto. After much discussion, scientists decided that Pluto would no longer be considered a planet, but would instead be part of a subcategory called dwarf planets. To explore the controversy further, you can provide students with a description of each planet, including Pluto, the dwarf planets, and other objects in the Solar system, and have them create their own categories and provide justifications.

In addition to discussing the characteristics of the planets, students can work in groups to do research. Once they have learned about each of the planets,  they can apply their new knowledge to describe the challenges that astronauts would face on each planet and propose ways to survive in the varying conditions.

Another fun way to bring the solar system to life is to create a scale model. Students often make models of the system on their own, but they are usually not to scale. Students can use scale model calculators found on the Internet or take a look at this Bill Nye video to help them. What follows are more solar system lessons.  An alternative way to incorporate the idea of scale without the workload of actual models is to convert the distances between planets into a proportional number of paces.  The class can go out to the blacktop or playing fields and stand in the relevant positions holding a very simple version of the planet they represent, such as a ping pong ball, marble, or hula hoop.  Even this rough but often amusing method will show the huge difference between the inner planets and the students that have to count out paces to end up in the far corner of the field.

Solar System Lesson Plans:

Solar System

This lesson has students use paper cut outs and fasteners to help students model the revolution of the Moon around Earth and the Earth around the Sun.

Pocket Solar System

Students make a simple model of the solar system using fractions and a meter long strip of paper tape.

The Solar System

Students use mathematical concepts and graph paper to draw a representation of the solar system.