by Curious Kids is a series for children of all ages. If you have a question you want to answer from an expert, send it to curiouskidsus@theconversation.com.
Just how many stars are in space? – Meesong, Broolein, Massachusetts
Look at the sky in a clear night and you will see thousands of stars – about 6,000.
But that’s just a small fraction of all stars out there. The rest is too far away to see her to see her.
The universe, galaxies, stars
But astronomers like me have found out how to appreciate the total number of stars in the universe, what is, what exists.
Galaxies are distributed throughout the universe – stars, planets, gas and dust that are tied together.
Like humans, galaxies are diverse. They come in different sizes and shapes.
The earth is in the Milky Way, a spiral galaxy; His stars group in spiral arms that swirl around the center of the galaxy.
Other galaxies are elliptical type of egg shape and some are irregularly with a variety of shapes.
The galaxies count
Before calculating the number of stars in the universe, the astronomers must first estimate the number of galaxies.
To do this, take very detailed pictures of small parts of the sky and count all the galaxies that you see in these pictures.
This number is then multiplied by the number of images required to take pictures of the entire sky.
The answer: There are approximately 2,000,000,000,000 galaxies in the universe – that’s 2 trillion.
The stars count
Astronomers don’t know exactly how many stars are in each of these 2 trillion galaxies. Most are so far that there is no way to say exactly.
But we can guess the number of stars on our own Milky Way. These stars are also varied and get a variety of sizes and colors.
Our sun, a white star, is medium -sized, medium and medium -sized: 27 million degrees Fahrenheit in its center (15 million degrees Celsius).
Larger, heavier and hotter stars are usually blue, such as Vega in the constellation Lyra. Smaller, lighter and dimered stars are usually red, such as proxima Centauri. With the exception of the sun, it is the closest star for us.
An incredible number
Red, white and blue stars emit different amounts of light. By measuring this star light – especially its color and brightness – astronomers can estimate how many stars our galaxy applies.
With this method, they discovered that the Milky Way has about 100 billion stars – 100,000,000,000.
Now the next step. With the Milky Way as a model, we can multiply the number of stars in a typical galaxy (100 billion) with the number of galaxies in the universe (2 trillion).
The answer is an absolutely astonishing number. There are about 200 billion trillion stars in the universe. Or, to express it differently, 200 sextillions.
That is 200,000,000,000,000,000!
The number is so large that it is difficult to imagine. But try the following: It is approximately ten times the number of cups of water in all oceans on earth.
Think about it the next time you look at the night sky – and then ask yourself what could happen on the trillion worlds that circle all of these stars.
Hello, curious children! Do you have a question you want to answer from an expert? Ask an adult to send your question to curiouskidsus@theconversation.com. Please tell us your name, your age and the city where you live.
And since curiosity has no age limit – adults, let us know what they are wondering. We will not be able to answer every question, but we will do our best.
This article will be released from the conversation, a non -profit, independent news organization that brings you facts and trustworthy analyzes to help you understand our complex world. It was written by: Brian Jackson, Boise State University
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Brian Jackson receives funds from NASA.
