The main difference between low Earth orbit (LEO) and geosynchronous orbit (GEO) lies in their altitudes, orbital characteristics, and purposes:
Altitude: LEO refers to orbits relatively close to the Earth's surface, typically ranging from a few hundred kilometers up to around 2,000 kilometers. On the other hand, GEO is a specific type of high Earth orbit situated approximately 35,786 kilometers (22,236 miles) above the equator.
Orbital Characteristics: LEO satellites orbit the Earth at a relatively fast pace, completing multiple orbits within a single day. They typically have orbital periods ranging from around 90 minutes to a couple of hours. Due to the relatively low altitude and fast orbital speed, LEO satellites are ideal for applications that require close proximity to Earth, such as Earth observation, remote sensing, and satellite communication constellations like Starlink.
In contrast, GEO satellites orbit the Earth at the same rotational speed as the Earth itself, making them appear fixed relative to a specific location on the ground. They have an orbital period of 24 hours, allowing them to remain stationary above a particular point on the equator. GEO orbits are commonly used for satellite communication, television broadcasting, and weather monitoring, as they provide continuous coverage over a specific region.
- Purpose: LEO and GEO orbits serve different purposes based on their unique characteristics. LEO satellites are advantageous for applications that require frequent revisits to different parts of the Earth's surface or low-latency communications. They are also useful for scientific research, space exploration, and monitoring environmental changes.
GEO satellites, with their fixed position relative to the ground, are beneficial for applications that require uninterrupted and continuous communication coverage over a specific area. They enable long-term, stable communications and are extensively used for broadcasting television signals, providing satellite-based internet services, and supporting global positioning systems (GPS).
In summary, LEO refers to low-altitude orbits with relatively fast orbital periods, suitable for applications that require close proximity to Earth. GEO is a high-altitude orbit with an orbital period of 24 hours, ideal for satellite communication and broadcasting purposes that require continuous coverage over a specific region.