How satellite tracking works
A satellite tracker starts with orbital elements that describe an object’s orbit at a reference time. Software propagates those elements forward to estimate position and velocity. Open-Galileo displays the result in an Earth-centered 3D scene and updates the simulation clock so users can compare live and accelerated motion.
The catalog identifies many objects with a NORAD catalog number. Search by common name or NORAD number, select an object, and inspect it relative to Earth. Because orbital elements age and atmospheric drag varies, displayed positions are estimates rather than navigational guarantees.
How to use the Open-Galileo satellite map
- Launch the explorer and keep Globe selected.
- Use Layers to make sure Satellites are visible.
- Search a spacecraft name or NORAD catalog number.
- Select the object to inspect details and focus the globe.
- Pause, run live, or accelerate time to watch the orbit evolve.
- Save an object and home location to prepare for pass-alert features.
Low, medium, and geostationary orbit
Low Earth orbit
Low Earth orbit, or LEO, contains many Earth-observation spacecraft, crewed vehicles, and communications constellations. These satellites move quickly across the local sky and complete an orbit in roughly an hour and a half to a few hours, depending on altitude.
Medium Earth orbit
Medium Earth orbit includes navigation constellations. Their longer orbital periods and higher altitude provide broad coverage while still moving relative to an observer.
Geostationary orbit
A geostationary satellite orbits above the equator with a period matched to Earth’s rotation. From the ground it appears nearly fixed in one direction, making the orbit useful for communications and weather observation.
Why satellites become visible
Most visible satellites do not emit their own light. They reflect sunlight. A favorable pass occurs when the observer is in darkness or twilight while the spacecraft remains illuminated above Earth’s shadow. Brightness also depends on distance, orientation, size, surface material, and atmospheric clarity.
Aircraft can resemble satellites at first glance, but aircraft usually blink, show colored navigation lights, or change apparent speed. A satellite typically looks like a steady point moving smoothly across the stars. Very bright flashes can occur when reflective surfaces align with the observer.