Satellit
A satellite is an object that orbits another object of larger mass. The term is most often used to describe a manufactured object intentionally placed into orbit around a celestial body such as a planet or moon. However, natural satellites, also known as moons, exist throughout the solar system and beyond.
Types of Satellites:
Satellites can be categorized in various ways, including:
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Natural Satellites: These are celestial bodies that orbit planets, dwarf planets, or asteroids. Examples include the Moon orbiting Earth, and Europa orbiting Jupiter.
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Artificial Satellites: These are man-made objects launched into orbit for a variety of purposes.
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Geostationary Satellites: Artificial satellites that orbit the Earth above the equator at the same rate as the Earth's rotation. This makes them appear stationary from the ground.
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Polar Orbiting Satellites: Artificial satellites that orbit the Earth in a north-south direction, passing over or near the poles.
Purposes of Satellites:
Artificial satellites serve a wide range of purposes, including:
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Communications: Relaying radio, television, and internet signals around the globe.
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Navigation: Providing precise location information for GPS and other navigation systems.
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Earth Observation: Monitoring weather patterns, environmental changes, and land use.
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Scientific Research: Conducting experiments in space and observing celestial objects.
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Military Intelligence: Gathering intelligence and monitoring enemy activities.
Orbital Mechanics:
The orbit of a satellite is governed by the laws of physics, primarily Newton's law of universal gravitation and Kepler's laws of planetary motion. The altitude, inclination, and eccentricity of an orbit determine the satellite's path around the primary body.
Deorbiting and Space Debris:
When a satellite reaches the end of its operational life, it may be deorbited, meaning it is guided back into the Earth's atmosphere to burn up. However, many defunct satellites and pieces of debris remain in orbit, posing a hazard to operational satellites and future space missions. This space debris is a growing concern and efforts are being made to mitigate its impact.