Technology is the use of knowledge to do things in a way that we can repeat. We use technology in many things like cooking, building, and even on our computers. It helps us do things in everyday life and in jobs like science and engineering. Long ago, people made simple tools from stone, and then learned to use fire. These helped humans to grow and talk to each other. Later, the invention of the wheel let people travel further and make better tools and machines. More recently, things like the printing press, telephone, and the Internet changed the way we share information and talk to each other. This has helped us learn a lot and quickly. But technology can also cause problems like dirt in the air or using up all of something. Sometimes, new machines can do jobs that people used to do, which means those people need to find new jobs. People think a lot about how we should use technology, how to make sure it is good, and how to fix any problems it causes. The word "technology" comes from a Greek word that means 'studying how to make things.' A very long time ago, the word meant knowing how to do different things, like making a building, sailing a ship, or printing words on paper.

People have been learning about the Solar System for a very long time. The Solar System is our home in space. It includes the Sun, the Earth where we live, the Moon, and other planets like Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune. There are also smaller space things like comets and asteroids. A long time ago, people could only see the Sun, the Moon, five other planets, and some other space lights with their eyes. They used shapes to study the stars. Then, they made a tool called a telescope that let them see much more. With the telescope, people found new moons and rings around planets, and also new planets, comets, and asteroids. They learned that planets are worlds like Earth, and that the stars are like our Sun. They started to understand how far away some stars are. For a long time, people thought the Solar System was the whole universe. But later, they learned it was just a part of a much bigger space. They used different ways to learn about the stars and planets, like studying the light they give off. Robots and astronauts have gone to space. They have landed on the Moon. There are also big telescopes in space. All these have helped humans learn a lot about space, like what the air and ground on other planets are like.

Stars are very bright and they can make it hard to see the planets that go around them. Planets don't make their own light and are much dimmer compared to stars. Because of this, seeing planets that are far away in space, which we call "exoplanets," is difficult. We can hardly see them with our eyes or even with telescopes. This is why people who study stars and planets, called astronomers, often have to use special ways to find these exoplanets. Astronomers have found some clever methods to discover new planets around other stars. Here's one way they do it: Imagine a star with a planet going around it. The planet's pull makes the star move a little bit in a circle. We can't see this movement easily, but we can measure how fast the star is going towards or away from us. This change is because of something called the Doppler effect. It helps astronomers find planets we can't see. They use very good tools to measure this. One of these tools is called a spectrometer, and it can see changes in the star's speed that are even slower than a person walking. This helps to tell if there's a planet there that we can't see with our eyes. So, even though planets near other stars are hard to see, astronomers can still find them by looking at how stars move!