Amazing Facts About the Universe and Space for Kids

The universe is a word we use to describe everything that exists in space. Some things that exist in the universe are galaxies, stars, planets, nebula, black holes and comets. Most of the universe is made up of empty space. The universe is enormous. The distances between each star in space are huge.

We don't know how big the universe actually is. It is made up of millions of galaxies. We live in a spiral galaxy called the Milky Way. Our planet seems so big to use. But Earth is just a small dot in the vast universe. These are some facts about the universe we live in.

To understand how vast the universe is, you have to know how distances are measured in space. We use light years to measure this. A light year is the distance that light can travel in one year. Light moves very fast. It travels at 186,000 miles (300,000km) per second. That's 5.88 million miles (9.46 million km) per year.

It can take years for the light from a particular star to reach Earth. If a star is 10 light years away, the light that leaves it now won't reach Earth for 10 more years. When you look into space, you are looking into the past. You are seeing how stars looked years ago.

There are millions of galaxies in the universe. Galaxies are collections of stars. And they are huge. Our Milky Way galaxy is 100,000 light years across. Yet it's just one small speck in the universe. The furthest galaxy we know, MACS0647-JD, is about 13.3 billion light years away. So, it took more than 13 billion years for light from that galaxy to reach us.

So, there are millions of galaxies in the universe. And there are millions of stars in each one. A star is a hot ball of gas. It produces heat and light using something called nuclear reactions. Stars come in lots of different sizes and colors. So, how many stars are there? By some estimates as many as 70,000,000,000,000,000,000,000. That's 70 sextillion stars.

Stars are born in clouds of gas and dust called nebulae. Some are bright and some are dark. The gas and dust in a nebula swirls around and around. Eventually clumps start to form. These clumps finally become stars.

The sun is the closest star to Earth. It provides us with the light and heat we need. It is 94 million miles (150 million km) away. It takes about 8 minutes for the sun's light to reach use. Compare that to the second closest star to Earth. It is called Proxima Centauri. It takes about 4 1/2 years for its light to reach us.

There are different types of stars. Our sun is a yellow dwarf star. It is about 4.5 billion years old. Billions of years from now, it will expand and become what is known as a red giant star.

Our planet Earth is one of 8 major planets that orbit the sun. The sun and everything that orbits around it is called the Solar System. Our solar system is just one of many in our vast, amazing universe.