Home
Assignments
Bookmarks
Satellites
The path followed by an object in space circling another object is called __________.
Kim and Philip are looking for a picnic spot. Philip is navigating using a map on his phone. I can’t see anything on this map, it doesn’t show the details! Maybe we should switch to a satellite view? Okay!
But, wait! What?! Why do we need a space rocket for that?! Whaaaaaaa…! We’re going to get a real satellite view.
But what is a satellite? A satellite is an object in space that circles around - orbits — another object in space. Moons are examples of natural satellites. A moon goes around a planet at a stable pace along a path we call an orbit. Some planets have many natural satellites - Saturn has as many as 82 moons circling around it!
But the Earth’s only natural satellite is the Moon. There are, however, many artificial, man-made objects in space that orbit the Earth. We call these artificial satellites. The first such object was launched into space in 1957 by the Soviet Union. It was named Sputnik.
Sputnik was about the size of a beach ball and made of aluminium. Inside, it had radio transmitters that sent signals, which could be detected all over the world. The successful launch of Sputnik opened new opportunities to explore space and learn more about our own planet. Modern satellites are more complex than the first Sputnik. Satellite’s main platform contains the engine and computer systems to control the satellite.
Attached to the platform are antennae — needed to receive and send signals, as well as other instruments, such as cameras or telescopes. Large “wings” covered with solar cells provide the satellite with energy - the sun is the satellite’s only source of power! The solar power can be stored in batteries and then used when the satellite is in shadow. Today, there are thousands of artificial satellites orbiting the earth along different paths, at different heights and different speeds. What do all these satellites do?
Many satellites are used to study the history of the universe, discover distant galaxies, or learn more about the possibilities of living in space. One of the most well-known satellites is the International Space Station, also known as ISS. For about 20 years ISS has been hosting crews of scientists from different countries, who conduct experiments in astronomy, biology, physics or medicine. Another satellite that is very important for research is the Hubble space telescope. It looks away from Earth into space and allows us to see distant comets, planets, and stars that can’t be seen from the earth itself.
Most satellites, however, are directly useful to every one of us. Some help us study weather around the world. People can measure temperature, air pressure, winds, and see how clouds move - all using satellites! This helps us predict weather. Other satellites carry different signals, allowing us to watch live TV broadcasts, listen to radio, make phone calls, or stream videos.
These satellites help us communicate with each other - they are communication satellites. Then, there are also satellites that record images of the earth’s surface. This allows us to track changes in the environment, for example melting glaciers, or forest fires. But it also helps us create very accurate and detailed maps of our planet! And the Global Positioning System - GPS, uses satellites to help us find locations and navigate those maps!
Hey, next time, let’s just use the satellites that people have already sent into space, alright? And we should remember to check the weather forecast too!