Comets are objects in space that are made up of ice and rock. They are faster than asteroids, which makes them very dangerous if they hit earth.
Some objects are “close by” and circle the sun in less than 100 years. They come from the Kuiper Belt. Other comets that take longer to make their orbit originate in the Oort Cloud.
Even out past the Oort Cloud is not the end of our solar system. The sun is the center of our solar system, so our solar system ends where its reach ends. Where the solar winds of our sun start to mix with the wind of other stars, that’s the end our solar system. That’s trillions of miles away.
The worlds in our solar system include not only the planets but also the moons. There are nearly 100 worlds that we know of in our solar system. The moons and the planets are all rocks. The planets orbit the sun. A moon orbits a planet. Some moons are bigger than planets.
Jupiter has a moon with erupting volcanoes. It’s even believed that Jupiter has moons with water under its surface.