Gravity and Orbits Lesson


TEKS Science: 6.3A-D, 6.11B-C CCRS Science Standards: VIII-A5, IX-C1


Lesson Objectives:

  1. Students will identify advantages and limitations of models of the solar system
  2. Students will examine and judge scientific evidence and explanations using logical reasoning, experimental and observational testing.
  3. Students will give accounts of the impact of scientists’ contribution on current scientific thought and society.


Lesson Overview:

The lesson begins with the teacher leading a demonstration of spinning two washers attached to a string to show how planets that are closer to the sun revolve faster around the sun. The students are introduced to the Question of the Day: “How does gravity affect the motion of the planets?” The teacher leads a discussion on the contributions of Galileo and Newton to the study of gravity. Using the Gravity and Orbits PhET simulation, students work in pairs to study how gravity affects the motion of planets. By the end of the lesson, students will understand how the gravitational force between two objects increases as the amount of mass involved increases and/or the planet moves closer to the sun. In addition, the students will understand that certain limitations are involved with this simulation. For example, the simulation is not in 3D, the planets are not shown to scale, and the simulation is exhibiting a perfect system with no outside complexities affecting the orbits. As an extension, students will calculate the weight of an object on different planets to demonstrate an understanding of how the gravitational force on a planet contributes to an object’s weight. The lesson concludes with the students discussing possible careers related to space exploration and the future of our space programs.