Final answer:
To increase or decrease the size of an object's orbit, you can change its speed or its distance from the central object it is orbiting. Kepler's laws of planetary motion describe this relationship.
Step-by-step explanation:
In order to increase or decrease the size of an object's orbit, you need to change the object's speed or its distance from the central object it is orbiting. If you increase the speed of the object while keeping the distance constant, the orbit will become larger. On the other hand, if you decrease the speed while keeping the distance constant, the orbit will become smaller.
For example, if you imagine a satellite orbiting the Earth, increasing its speed while maintaining the same distance from the Earth will make its orbit larger and increasing its speed while moving it closer to the Earth will also make its orbit larger. Similarly, decreasing its speed while maintaining the same distance or moving it farther away from the Earth will make its orbit smaller.
This relationship between speed, distance, and orbital size is described by Kepler's laws of planetary motion.