Satellites

Definition

Satellites are objects that orbit a larger body, such as a planet or a star, due to the force of gravity. They can be natural, like moons, or artificial, like the ones humans have launched into space to study the Earth, communicate, and explore the universe.

5 Must Know Facts For Your Next Test

1. Satellites are held in orbit by the force of gravity, as described by Newton's Universal Law of Gravitation.
2. The period of a satellite's orbit is determined by its distance from the body it orbits, as described by Kepler's Third Law.
3. Artificial satellites are used for a variety of purposes, including communication, navigation, weather monitoring, and scientific research.
4. The motion of satellites is governed by the principles of orbital mechanics, which take into account the effects of gravity, momentum, and other forces.
5. Satellites can be classified as either geostationary, which maintain a fixed position relative to the Earth's surface, or non-geostationary, which have more variable orbits.

Review Questions

• Explain how the force of gravity affects the motion of a satellite orbiting a planet.
  • According to Newton's Universal Law of Gravitation, the force of gravity between a satellite and the planet it orbits is directly proportional to the masses of the two objects and inversely proportional to the square of the distance between them. This gravitational force provides the centripetal force necessary to keep the satellite in a stable, elliptical orbit around the planet. The strength of the gravitational force determines the satellite's orbital period and velocity, as described by Kepler's Laws of Planetary Motion.
• Describe the different types of satellite orbits and their applications.
  • Satellites can be classified into different types based on their orbital characteristics. Geostationary satellites maintain a fixed position relative to the Earth's surface, making them useful for communication and weather monitoring. Non-geostationary satellites, such as those in low Earth orbit or polar orbits, have more variable orbits that allow them to cover different regions of the Earth. These satellites are used for a variety of purposes, including scientific research, Earth observation, navigation, and military applications. The choice of satellite orbit depends on the specific objectives and requirements of the mission.
• Analyze how the principles of orbital mechanics, including Kepler's Laws and Newton's Universal Law of Gravitation, govern the motion and behavior of satellites.
  • $$The motion of satellites is governed by the principles of orbital mechanics, which are based on Kepler's Laws of Planetary Motion and Newton's Universal Law of Gravitation. Kepler's First Law states that satellites orbit in elliptical paths, with the body they orbit at one of the foci. Kepler's Second Law describes how a satellite's orbital velocity varies, with the satellite moving faster when closer to the body it orbits and slower when farther away. Kepler's Third Law relates a satellite's orbital period to its distance from the body it orbits, providing a way to predict the satellite's motion. Newton's Universal Law of Gravitation explains the force that keeps the satellite in its elliptical orbit, with the strength of the gravitational force determining the satellite's velocity and period. Understanding these fundamental principles of orbital mechanics is crucial for designing, launching, and maintaining functional satellite systems.$$

Related terms

Orbital Mechanics: The study of the motion of objects, such as satellites, in orbit around other bodies due to the force of gravity.

Gravitational Acceleration: The acceleration experienced by an object due to the force of gravity, which determines the motion of satellites and other celestial bodies.

Kepler's Laws of Planetary Motion: A set of three laws that describe the motion of planets and other objects, including satellites, in elliptical orbits around the Sun.