Man-made satellites and what they are used for
Physics · Key Stage 2 · The School
What keeps a satellite up there
A SATELLITE is anything that orbits a larger body. The Moon is a NATURAL satellite of the Earth. Thousands of MAN-MADE satellites also orbit the Earth. Rockets launch them up there. A satellite stays in orbit because it is always falling towards the Earth. But it is also moving forward fast enough to keep missing. This is the same idea as gravity curving a thrown ball's path, just at a much bigger scale.
What satellites are actually used for
Weather satellites photograph clouds from above. That feeds the forecasts you see every day. Communication satellites relay phone calls, television and internet signals around the planet. Navigation satellites are used by GPS. They let a phone work out its own position. It does this by comparing signals from several satellites at once.
Not everything up there is the same
Different satellites orbit at very different heights, for different reasons. Some circle close to Earth. They complete an orbit in around ninety minutes. Others sit much further out. These match Earth's own spin, so they appear to hang over the same spot all day. That is useful for a satellite dish, which then never needs to move.
A weather satellite orbits far above the Earth. It takes a photograph of a swirling cloud pattern over the ocean. That image is beamed down to a ground station, using a radio signal. Forecasters combine it with dozens of other satellite images taken that same day. Together, these help predict where a storm will move next. None of this needed a person or a plane anywhere near the storm itself. The whole forecast started with a machine, quietly orbiting, looking down.