Do you know about The Milky Way? 🌌

00:00:00
Speaker 1: You're listening to sleep Tight Science. Did you know that our Milky Way galaxy is constantly moving. What it's racing through space at a speed of about two point one million kilometers per hour or about one point three million miles per hour, so we're never sitting still. Hello, friends, and welcome back to sleep Tight Science, a bedtime show that answers your questions about science. Before we get started, we have a favor to ask getting your science questions, and even though we can't possibly answer them all, we use them to find out what you love to learn about. So if you have any questions, please send them our way. In return, we give you a small thanks in a form of a shout out at the end of our episode. Our email can be found in our show notes. We can't wait to see what you are interested in. In this episode, we are going to learn about our galaxy, the Milky Way, which is named for its soft, milky glow as it stretches across the night sky. Long ago, people thought it looked like a river of milk flowing through the stars. In Greek mythology, there's even a story that the goddess Hair sprayed milk across the sky creating this glowing band. Around the world, different cultures have special names for this starry path. It's called the Silver River, winding through the darkness like a shining ribbon in China. In the Kalahari Desert of South Africa, people call it the backbone of night, as if the stars are holding up the night sky. Each name gives us a unique way to imagine the Milky Way, a reminder that we're all looking up at the same galaxy, no matter where we live. Did you know that the Milky Way is three point six billion years old, one hundred thousand light years across, takes two hundred and fifty million years to run, rotate, and has over two hundred billion stars. Let's learn a bit more about our galactic home. Imagine a place so vast that you could travel your whole life and still barely scratch the surface. That's our galaxy, the Milky Way. This sprawling spiral galaxy is made up of stars, planets, gas, and dust held together by the powerful force of gravity. Think of the Milky Way as a massive city in space, home to over one hundred billion stars and counting all orbiting around a central core our solar system, including Earth sits in a a bourban part of this galaxy, about twenty seven thousand light years from the center. If the Milky Way were a bustling city, we'd be living in a quieter neighborhood called the Orion Sickness Arm, nestled between the larger Perseus and Carina Sagittarius arms. Fitcher our solar system as one tiny speck of sand on an enormous beach, looking up at the night sky. That faint, hazy band of light stretching across it is the glow of billions of distant stars in our galaxy, blending together in a soft shimmer. Just as Earth orbits the Sun, our entire solar system orbits the center of the Milky Way, traveling at about five hundred and fifteen thousand miles per hour or eight hundred and twenty eight thousand kilometers per hour. Yet it takes approximately two hundred and fifty million years to complete one full orbit, a cycle that last occurred when dinosaurs first roam the planet. Zooming out, we'd see the Milky Way's distinctive spiral shape, with its arms curving outward from a core packed with stars, gas, and dust. At the very heart of our galaxy is a super massive black hole, Sagittarius, a star with a mass of about four million suns. This immense force pulls in anything nearby, shaping and holding the galaxy together with its intense gravitational pull. The Milky Way belongs to a larger family of galaxies called the Local Group, with Andromeda and Triangulum as our nearest neighbors. One day, billions of years from now, the Milky Way and Andromeda might collide, merging into a new galaxy altogether. The Milky Way is constantly evolving. New stars are born in its spiral arms, while older stars drift toward the core. Some of the dust and gas in the galaxy eventually form new stars, planets, and even the building blocks of life. Everything around us, our bodies, the trees, oceans, and animals, is made from star dust, remnants of ancient stars from our galaxy and beyond. On a clear night, away from city lights, you can catch a glimpse of this bright galactic city stretching across the sky. The next time you see that faint band of light, remember you're looking at the Milky Way, our vast home in the universe. Did you know that the biggest star in our galaxy, called uy Scootie, is so large it could fit over one thousand and seven hundred of our stars inside it. If it replaced the Sun, it would stretch out past Jupiter. Now that we know a bit about the Milky Way, which while our home, it's just one of billions of galaxies, let's learn a bit more about galaxies in general. Galaxies are enormous collections of stars, gas, dust, and dark matter, all held together by gravity. They're like huge cosmic communities that can contain billions or even trillions of stars. Each galaxy is unique, with its own shape, size, and structure. Galaxies come in different shapes, each with its own unique features. Here are the three main types. Spiral galaxies have bright centers with swirling arms that wind outward in a spiral pattern. These arms are filled with gas and dust, which means they're busy with star formation. Young stars often light up these arms, making them look like glowing pathways. Our Milky Way is a spiral galaxy, and so is Andromeda, our nearest galactic neighbor. Elliptical galaxies have a different look. Instead of arms, they're shaped like stretched out circles or ovals with stars spread evenly throughout. They often contain older stars and have less gas and dust, meaning fewer new stars form. Elliptical galaxies can range from small to massive, sometimes containing trillions of stars. Irregular galaxies don't have a defined shape. They can look like scattered clouds of s stars and gas. They might have been pulled out of shape by the gravity of nearby galaxies, or they may just be forming their structure. These galaxies often have young stars and lots of gas, giving them a more dynamic, ever changing look. Each type of galaxy adds to the variety in the universe, giving scientists clues about how stars form and evolve, whether they're spirals, ellipses, or irregular shapes. Galaxies help us understand the vastness of space and our place in the cosmos. Did you know some stars in the Milky Way are over thirteen billion years old. These stars are older than our Sun, which is already around four point six billion years old. Let's use our imaginations and picture heading off on a journey far beyond our galaxy the Milky Way, into the unknown depths of space. Wouldn't that be fun to travel that far? We need technology that doesn't exist yet, and that's where our imaginations come in. The distances between galaxies are so vast that even light, which is the fastest thing in the universe, would take millions of years to get to the nearest ones. So we'll need some futuristic technology who make such a trip even close to possible. One idea scientists imagine is something called a warp drive. This powerful engine could bend or warp space itself, shrinking the distance between galaxies so that we could travel faster than the speed of light. A warp drive could make it possible to reach other galaxies in just a few years instead of millions. Right now, it's only science fiction, but scientists are studying the idea to see if it could one day become real. We'd also need a ship that could support life for a long time, maybe even for generations. What could we call this ship? I think we would call ours the sleep Tight Explorer. Our sleep Tight Explorer ship would have to grow food, recycle water and air, and have enough space for people to exercise and stay healthy. Imagine floating around in a giant spaceship with gardens, living spaces, and even labs where scientists could study what they find along the way. Then there's artificial intelligence or AI, which would be super important on a journey this long. Robots and AI could help control the ship, fix any problems, and even work with astronauts to keep everything running smoothly. They might even help look for signs of life in other galaxies. For now, exploring beyond the Milky Way remains a dream or something we see in movies. Still, every bit of science and technology we invent today gets us a little closer. So maybe in the future you could be the first to explore the galaxies far beyond our own. Did you know that in nineteen seventy seven, a mysterious radio signal from space was detected. It was so unusual that astronomer Jerry Emmon wrote wow next to it on the data. Today it's known as the Wow signal, and we still aren't sure where it came from. Did you ever wonder if there is life beyond our galaxy? Maybe some extraterrestrials might someday come and say hello. One of the biggest questions in science is are we alone in the universe? With billions of stars in our galaxy, each with the potential to have planets of their own. Scientists and non scientists alike can't help but wonder if some of those planets might have life. Searching for life beyond Earth is very exciting, and scientists use many tools and methods to find places in our galaxy that might support life. To start, scientists look for planets in what's called the Goldilocks zone. This is a zone around a star where temperatures are just right, not too hot, and not too cold for liquid water to exist. Water is essential for life as we know it, so finding planets with the right conditions is a big first step. Scientists use powerful telescopes like the James Web Space Telescope to study distant planets and see if they have the right characteristics to support life. Another tool scientists use is spectroscopy, which involves studying the light that comes from distant planets. Scientists can tell what gases are in a planet's atmosphere by examining the light. For example, finding oxygen or methane in an atmosphere could be a hint that life processes are taking place. Certain gases like these don't last long without something to constantly produce them. Their presence could be a clue. There are also projects like SETI Search for Extraterrestrial Intelligence, where scientists use radio telescopes to listen for signals from other civilizations. They hope that if other intelligent life exists, they might be trying to communicate with us using radio waves. So far, we have yet to find any messages, but the search continues, with new tools and ideas being developed all the time. While we have yet to find direct evidence of life outside Earth, the search is far from over. Every discovery of a new planet or strange signal brings us closer to understanding whether or not we are alone in the galaxy. One day, we'll finally get an answer to the question that's been on our minds for so long. In this episode, we learned about our home galaxy, the Milky Way. We explored what makes it so unique and fascinating. We learned that the Milky Way is a massive spiral galaxy home to over one hundred billion stars, including our own Sun, and stretches across an incredible distance in space. Our Solar system is situated in a quieter, suburban region of the galaxy, nestled within the Orion signis Arm about twenty seven thousand light years from the galactic center. We discovered that the center of the Milky Way holds a super massive black hole called Sagittarius, a star which has a powerful gravitational pull that helps keep the galaxy together. We also explored the three main types of galaxies, spiral, elliptical, and irregular, and discussed how each has its own structure and characteristics. Spiral galaxies like the Milky Way have sweeping arms filled with stars, gas, and dust, while elliptical galaxies have a more rounded shape and irregular galaxies have no clear structure. We also looked beyond our galaxy, imagining the technology that might one day allow us to explore the universe beyond the Milky Way, like warp drives and long term spacecraft. Finally, we pondered one of the biggest questions of all, are we alone in the galaxy. We learned about the search for extraterrestrial life, including the Goldilocks zone, where conditions are just right for liquid water and potentially life. Using powerful telescopes and tools like spectroscopy, scientists look for planets with the right conditions to support life. Even though we don't yet have answers, the ongoing search keeps us hopeful and curious about what and who might be out there. Thank you to Misha Sheath from Travers Road. I hope I said your name correctly who introduced our show. You were super awesome. Thank you to six year old Tessa in Melbourne, Australia, who is six years old, Isaac who is four years old from Saint Elmo, Chattanooga, Tennessee, Leandra in fourth grade, Ion Argaval seven years old from Dublin, Ohio, Alisha eight years old from Finland, Melody Rico age nine from California, Alex seven years old from Wales, Beatrix six years old from Portland, Oregon, and Vishwak Pendula age eight years old. We would love to hear from you. Ask your parents to help you. Write us a note to the email address in our show notes. You can also visit our website and send a message that way. Also leave us a rating or a comment. Wherever you listen to our podcast, we love to get your feedback. If you want to make sure you get all the episodes, please ask your parents to follow us on Apple Podcasts, Spotify or all the other cool ways you can follow us. If you'd like to send us your questions, please send them to hello at sleeptightscience dot com. Did you know your brain can go on amazing adventures When you sleep, you might dream about some of the cool things we talked about, like soaring through the Milky Way, lying through space past gigantic stars, or even drifting along on a sparkling, icy glacier. Maybe you'll imagine raindrops falling, explore how the skeleton protects your organs, or picture yourself as a scientist discovering why ice cracks when it melts. Your dreams can take you anywhere, and who knows, maybe tonight you'll dream about uncovering something new and exciting in the world of science. Good Night, sleep tight.