Satellites and GPS Lesson 38 of the technology course of Mova's primary school: 19 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 A satellite does not float in space; it is falling all the time. 1 It was thrown sideways so fast by a rocket that as it falls, the round Earth curves away beneath it, so it keeps falling around the Earth and never hits the ground, like a ball thrown so hard it would go right round the world. 2 Thousands of satellites are up there doing jobs. 3 Some photograph clouds for the weather forecast, some beam TV to the dishes on your street, some carry internet to farms and ships, and some help your phone know where it is. 4 GPS works like a game of listening. 5 Each GPS satellite keeps perfect time with an atomic clock and keeps calling out the time. 6 Your phone hears several of them, works out how long each call took to arrive, and from that how far away each satellite is, and so exactly where you are. 7 Space is getting crowded, too: old satellites and broken pieces race round the Earth as space junk, and even a fleck of paint at that speed can damage a spacecraft. 8 A satellite is a machine launched into orbit, falling around the Earth fast enough that it never hits the ground; there are thousands of working satellites around Earth. 9 GPS works because a phone listens for timing signals from several satellites and works out where it is from how long the signals took; GPS satellites carry very precise atomic clocks. 10 GPS is run by the US Space Force, and Europe runs its own system called Galileo. 11 A sat nav uses GPS for its position and a stored map to find a route; the driver must still watch the road, because sat navs have sent lorries down tiny lanes. 12 A satellite TV dish collects weak signals from a satellite far above the equator and focuses them onto a receiver, so in the UK all the dishes on a street face south-east, the same way. 13 Weather satellites photograph clouds and measure temperatures, which helps forecasters predict storms days ahead. 15 A rocket burns fuel and pushes hot gas downward very hard, which pushes the rocket up into space, and some rockets now land back on Earth to be used again. 16 The International Space Station is a big laboratory orbiting Earth with astronauts on board, and it goes around the Earth about every 90 minutes; the astronauts float because they and the station are falling around the Earth together, though gravity is still there; you can sometimes see it from the ground as a bright moving dot. 17 Space junk is broken satellites and pieces orbiting Earth very fast, and space agencies track it because even a small fleck of paint can damage a spacecraft. 18 A map app combines GPS with maps and live traffic from many phones: when lots of phones on one road move slowly, it shows a jam. 19 Share your location only with your family. ← previous The internet and undersea cablesnext → Robots at work and at home↑ back to Technology This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/technology/38-satellites-and-gps/