Here's why:
* Total Energy: The total energy of a satellite is the sum of its kinetic energy (energy of motion) and potential energy (energy due to its position in the gravitational field).
* Conservation of Energy: In a closed system like a satellite orbiting a planet, the total energy is conserved. This means that energy cannot be created or destroyed, only transferred or transformed.
* Trade-off: As the satellite moves closer to the planet, its potential energy decreases (becomes more negative). This is because it's closer to the gravitational pull. However, this decrease in potential energy is balanced by an increase in kinetic energy, as the satellite speeds up.
Therefore, the total energy of the satellite remains constant throughout its elliptical orbit.
It's important to note that the satellite's speed and potential energy vary at different points in the orbit, but the total energy remains the same.
