Lesson: Motion of Planets, Moons, and Satellites Physics • First Year of Secondary School

Students will be able to

• state the two main types of orbit: circular and elliptical,
• recognize the two main types of orbits from diagrams,
• recognize that if two objects (such as a star and a planet) are closer to each other, the force of gravity between them will be greater,
• know that for an object in orbit, the force of gravity is always in the direction of that which it’s orbiting,
• know that for an object in a circular orbit, the force is always perpendicular to the velocity,
• know that for an object in a circular orbit, the acceleration of the object is always in the direction of that which it’s orbiting and always perpendicular to the velocity,
• know that for an object in a circular orbit, the smaller its orbital radius, the greater its orbital speed,
• know that for an object in an elliptical orbit, when it is closer to that which it’s orbiting, its speed will be greater,
• know that the period of a geostationary orbit must be 24 hours,
• know that a geostationary satellite must orbit above the equator.