A satellite is any object that orbits another in space . The Moon is Earth's natural satellite . But since 1957 we have also sent thousands of artificial (human-made ) satellites into orbit . Right now, thousands of these machines are circling our planet , quietly helping with all sorts of everyday tasks .
✨ The very first artificial satellite was Sputnik 1, launched by the Soviet Union on 4 October 1957. It was about the size of a beach ball and beeped a radio signal as it orbited Earth .
Why does a satellite stay up instead of falling back down ? It is actually falling all the time — but it is also moving sideways so fast that it keeps missing the Earth . This perfect balance between falling and racing forward is what we call an orbit . Cut the speed and it would spiral down ; speed it up too much and it would fly off into space .
📷 European Space Agency · CC BY-SA 3.0 igoToday satellites do an astonishing number of useful jobs . Communication satellites relay phone calls , television signals , and internet data across the globe . Weather satellites photograph clouds and storms , helping forecasters warn us of bad weather days in advance . Navigation satellites — the GPS system — let your phone tell you exactly where you are.
🗂️ Sort each satellite job into the right category.
Communication Observation Navigation
Communication Observation Navigation
Communication Observation Navigation
Communication Observation Navigation
Communication Observation Navigation
✨ Earth observation satellites can measure the temperature of the ocean , spot wildfires from above , and track how quickly glaciers are melting — information that helps us understand and protect our planet .
Satellites are launched by rockets and placed in orbit at different heights . Low Earth orbit satellites are just a few hundred kilometres up and complete one orbit in about 90 minutes . The International Space Station is one of these. Higher up, geostationary satellites sit about 36,000 km above the equator and appear to hover in the same spot , which makes them perfect for TV and communications .
📷 NASA Goddard Space Flight Center from Greenbelt, MD, USA · Public domain🔗 Match each satellite idea to what it means.
Satellites that help find your location Appears to hover over one spot on Earth A few hundred kilometres up, fast orbits The curved path a satellite follows around Earth
Satellites that help find your location Appears to hover over one spot on Earth A few hundred kilometres up, fast orbits The curved path a satellite follows around Earth
Satellites that help find your location Appears to hover over one spot on Earth A few hundred kilometres up, fast orbits The curved path a satellite follows around Earth
Satellites that help find your location Appears to hover over one spot on Earth A few hundred kilometres up, fast orbits The curved path a satellite follows around Earth
How does GPS know where you are? Your device listens for signals from several navigation satellites at once . By measuring how long each signal took to arrive , it can work out its distance from each satellite , and then pinpoint your exact spot on the map. It usually needs signals from at least four satellites to be accurate .
⚠️ Old satellites that stop working become space debris — junk floating in orbit . Space agencies work hard to track these objects to keep working satellites safe .
✍️ Fill in the satellite facts.
The first artificial satellite was called _____ . The system that helps your phone find your location is called _____ . A satellite that appears to hover over one spot is in a _____ orbit .
Sputnik 1 GPS geostationary Hubble Apollo
