What does a satellite do?

A satellite is any body or object that moves around another; for example, the Moon is a satellite of Earth. But when most scientists use the word “satellite” they are referring to a man-made object that orbits Earth and collects and returns data. A single satellite may serve many purposes. Satellites can be used for weather forecasts by measuring clouds, winds, and the temperature of the atmosphere from space. They are also used in military contexts to track battle zones, watch for missile launches and nuclear testing, spy on countries, and track incoming objects like meteoroids. Satellites also send television programs and telephone calls from one continent to another. The first Global Positioning Satellite (GPS) was launched on November 22, 1978, and today GPS is the standard navigation tool used by the military, scientists, and industry. Space satellites are used for learning about the universe, including how the Sun and Earth interact and details about planets.