The Milky Way is a barred spiral galaxy that is part of the Local Group of galaxies. It is located in the Virgo Supercluster and can be seen from Earth as a band of stars in the night sky. Our solar system is located within the Milky Way, about 27,000 light-years away from its center. The exact location of the Milky Way within the universe is constantly changing as it is influenced by the gravitational forces of other galaxies. Despite its vast size, the Milky Way is just one of billions of galaxies in the observable universe.
If someone asks you where you live, you would probably mention the name of your street or the town you come from. If you’re on vacation, you might even mention your state or country.
But what if aliens asked you? If you said Earth, they might not have any idea what or where Earth is. You would have to tell them which galaxy you live in. Have you ever thought of yourself as a resident of a galaxy? Well, you are! And it’s called the Milky Way.
A galaxy is a massive collection of stars held together by gravity. How massive? Consider this: Our star, the Sun, is just one of about 200 billion stars in the Milky Way! Almost everything we see in the sky is part of our galaxy.
The Milky Way is a type of galaxy called a barred spiral galaxy. This means it resembles a thin disk with spiral arms extending outward. Our solar system can be found on one of the outer edges of the galaxy, along one of the spiral arms.
The Sun is approximately 25,000 light years away from the center of the Milky Way. Overall, the Milky Way is 80,000-120,000 light years wide, but only about 7,000 light years thick.
These measurements are difficult to comprehend. To give you an idea of the size of the Milky Way, imagine shrinking it down to the size of a football field. Our solar system would then be equivalent to a grain of sand located on one of the outer edges.
Our solar system orbits around the Milky Way at a speed of about 155 miles per second. That’s incredibly fast! However, the Milky Way is so vast that it takes our solar system approximately 200-250 million years to complete one orbit around it!
You may come across images of the Milky Way from time to time. These are not actual photographs, as we have never sent a spacecraft beyond the Milky Way. However, special telescopes enable astronomers to gather a wealth of information about our galaxy. Its hazy, “milky” appearance is what gave it its name.
As enormous as the Milky Way is, it is just one of the galaxies within a group known as the Local Group, according to astronomers. To make you feel even smaller, astronomer Edwin Hubble demonstrated in the 1920s that the Milky Way is merely one of approximately 200 billion galaxies in the universe!
And in terms of galaxies, the Milky Way is not even close to being the largest. Astronomers believe that the nearby Andromeda Galaxy may contain as many as one trillion stars! Will humans ever visit Andromeda? Perhaps! And from there, maybe we will explore even more distant corners of the universe.
Give It a Try
Are you up for exploring your galaxy? Enlist the help of a friend or family member to tackle the following activities:
- If you want to explore the Milky Way, you don’t need a spacesuit. Just use your computer and go online to check out these sky tours. If you could go anywhere in the Milky Way, where would you choose to go and why?
- If you’re interested in seeing more images of the Milky Way taken by NASA, take a look at these fascinating online photo galleries. Isn’t it amazing how telescopes enable scientists to capture pictures of objects so far away? Which of these pictures do you find the most intriguing? Explain what you learned about the photographed object to a friend or family member.
- We find it fascinating how the pictures of the Milky Way resemble art. If you want to create your own version of the Milky Way, follow the instructions to make a Glitter Galaxy Craft! Can you make it resemble the Milky Way?
Sources of Wonder
- http://en.wikipedia.org/wiki/Milky_Way (accessed on July 21, 2020)
- http://www.atlasoftheuniverse.com/milkyway.html (accessed on July 21, 2020)
- http://map.gsfc.nasa.gov/universe/rel_milkyway.html (accessed on July 21, 2020)