Methods of detecting exoplanets
Planets are very hard to see because their star shines so much brighter. It's like trying to find a tiny light next to a big flashlight. Most of the time, we can't see planets around other stars with our eyes or cameras.
To find these far away planets, scientists use special ways to look for them. They watch how stars move. Stars move a little because of the gravity from planets. This wobble can tell scientists there is a planet there.
One way scientists use is called the "radial velocity" method. They look at the star's light and if the light changes, it means there is a planet. They use special tools like HARPS and HIRES to do this. These tools are very good at seeing small changes in how the star moves.
Sudarsky's gas giant classification
Big planets far from their stars are called gas giants. A man named David Sudarsky made a way to guess what they look like. The way to guess uses numbers and letters. Big planets like Jupiter and Saturn fit in this way to guess.
We don't know what planets that are not like Jupiter or Saturn look like because they are too hard to see. We can sometimes use special tools to learn about big, hot planets close to their stars. These big, hot planets are different colors.
When we want to know what other big planets far away look like, we use computers to help us guess. These big planets have clouds made of something called ammonia. They are very far from the little lights in the sky called stars.
Technology is like a tool. It helps us do things better and easier. People use technology every day at home and work. Long ago, people made tools from stone. This was the first technology. Then, they learned how to use fire, which helped them grow. Later, they made the wheel which helped them move and build bigger things.
Now, we have new things like the printing press, the telephone, and the Internet. These make talking and sharing information easy. They help everyone learn more. But, sometimes technology can be bad. It can make the air dirty or use up the Earth's things. It can also take away jobs. People think and talk about how to use technology in a good way.
The word "techology" came from a Greek word. It means to know how to make things. In the past, it was for all kinds of making, like building, dancing, or sailing ships. Now, we use it for machines and programs that help us do things.