Beyond Neptune, there is a region of ice. We call this area the Kuiper Belt. It is full of small, icy objects. This is where we find the dwarf planets. The most famous dwarf planet is named Pluto. For a long time, Pluto was the ninth planet. However, scientists changed its name in 2006. They decided that Pluto was too small. Therefore, it became a dwarf planet instead. Pluto has five moons and a heart shape. This heart is a big glacier of nitrogen ice. Because it is so far, it is very dark.
There are other dwarf planets in this belt too
For instance, Eris is almost as big telemarketing data as Pluto. Also, we have Haumea and the planet Makemake. These worlds are very hard to see from Earth. We need very powerful telescopes to find them. In addition, some of them have their own moons. Scientists want to learn more about these cold worlds. They tell us about the early solar system. Because they are frozen, they are like time capsules. They hold secrets from billions of years ago. Furthermore, the New Horizons probe visited Pluto recently. It sent back the first clear pictures we have. Indeed, these small worlds are full of big surprises.
Asteroids and Comets in Space
There are many smaller rocks in our system. Most asteroids live in the Asteroid Belt. This belt is between Mars and Jupiter. Asteroids are rocky pieces that never became planets. Some are huge, but most are very small. Sometimes, they crash into each other in space. On the other hand, we have objects called comets. Comets are like giant, dirty snowballs in space. They are made of ice, dust, and rock. When they get near the sun, they melt. This creates a long, glowing tail behind them.
This tail always points away from the hot sun.
People have seen comets in the sky for years. Some comets visit us every few decades. For example, Halley’s Comet comes every seventy-six years. Watching a comet is a very special event. In addition, some rocks fall toward the Earth. We call these falling rocks meteors or "shooting stars." Most of them burn up in the air. Therefore, they do not hit the ground at all. However, some large ones do land on Earth. These are called meteorites and scientists study them. They give us clues about what space is made of. Consequently, even small rocks are very important to science.