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Aliens & Exoplanets

Nov 20, 2024

10 min read

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Podcast Title: Stuff For Kids


Episode Title: Aliens & Exoplanets


Teaching Resources & Lesson Plans (Coming Soon)


Listen to Episode Here




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Narrator:  

Hey, everyone! Welcome back to Stuff For Kids! I’m Sam, and today we’re blasting off into the great unknown — exploring deep space, distant worlds, and the biggest question of all: Are we alone in the universe?


Before we jump in I just want to remind you that we have an email address: stuffforkidspodcast@gmail.com - if you have any comments, suggestions or ideas - I’d love to hear from you.


Okay, so back to today’s episode - it’s all about exoplanets — planets that orbit stars beyond our own Sun — and the search for aliens. Yes, you heard that right! Scientists around the world are actually looking for signs of life on other planets. In fact, some of the smartest people on Earth are working on solving this cosmic mystery right now, and you’ll find out all about their tools, techniques, and wildest theories.


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### Part 1: What Exactly Are Exoplanets?


Narrator:  

Let’s kick things off with some planet facts. You’re probably familiar with our own solar system — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. But the planets we see around our Sun are only a tiny part of what’s out there. Beyond our Sun are billions of other stars, and many of them have their own planets. We call these planets exoplanets.


What makes exoplanets so special? Well, they might be home to creatures we’ve never seen before or have landscapes that look nothing like Earth. The first exoplanet ever discovered was found in 1992 around a pulsar — a rapidly spinning star that gives off radiation. This was surprising, as scientists had no idea planets could orbit pulsars. Since then, astronomers have discovered over 5,000 exoplanets, each with unique features!


One exoplanet called HD 189733b is famous because it’s one of the windiest planets ever discovered. Winds there blow at over 8,600 kms per hour! Another planet, Kepler-16b, orbits two stars at once. Imagine having two suns in the sky! These exoplanets show us that our solar system is just one example, and there are countless other star systems with strange, amazing worlds waiting to be discovered.


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### Part 2: How Do Scientists Find Exoplanets?


Narrator:  

Exoplanets are incredibly far away from us — some are thousands of light-years from Earth. So, how do scientists even know these planets exist if they’re too small and far to be seen directly? They’ve come up with clever ways to spot these distant worlds, using powerful telescopes and techniques like the Transit Method and the Wobble Method.


The Transit Method is a bit like a shadow puppet show in space. When an exoplanet passes in front of its star, it blocks a tiny bit of the star’s light, causing a small “dip” in brightness. By studying these dips, scientists can figure out the size of the planet, its orbit, and sometimes even what its atmosphere might be made of! This method has helped us discover many exoplanets, especially with the help of telescopes like Kepler and TESS (Transiting Exoplanet Survey Satellite), which are designed to look for these tiny blips of light.


The Wobble Method works by watching the motion of stars. When a planet orbits a star, it creates a small tug on the star, making it “wobble” back and forth. By looking closely at these movements, astronomers can learn about a planet’s mass and orbit. This method is also called the Doppler Method because it uses something called the Doppler Effect — the same thing that makes a fire truck’s siren sound different as it drives past you!


Fun Fact: The smallest planet ever found with the Wobble Method is about the size of our Moon! Finding these tiny planets takes an enormous amount of patience and technology.


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### Part 3: The Search for Alien Life


Narrator:  

Now, on to the exciting part — the search for alien life! When scientists talk about searching for life on other planets, they don’t necessarily mean finding aliens that look like us or have spaceships. Even tiny, microscopic organisms would be considered life, and finding them on another planet would be a huge discovery!


For life as we know it to survive, water is super important. Here on Earth, wherever we find water — from deep in the ocean to icy glaciers — we find life. So scientists search for exoplanets that might have liquid water on their surfaces, which are in the habitable zone of their star. This zone is also known as the Goldilocks Zone — the spot where it’s not too hot, not too cold, but just right for water to stay in liquid form.


Some planets are even believed to have entire oceans hidden beneath their surfaces! For example, scientists think Jupiter’s moon Europa and Saturn’s moon Enceladus might have massive underground oceans. If these icy moons in our own solar system have hidden oceans, it’s possible that similar planets or moons in other star systems might too.


Another major clue in the search for life is the atmosphere of a planet. If a planet has an atmosphere with oxygen, methane, or other gases that we associate with life, scientists get very excited. These are called bio-signatures, and finding them could mean that life, even if it’s just tiny bacteria, might be there.


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### Part 4: Signs of Life — Bio-signatures and Techno-signatures


Narrator:  

Alright, now let’s dive a bit deeper into bio-signatures. As I mentioned, bio-signatures are chemicals in a planet’s atmosphere or surface that hint at the presence of life. On Earth, for example, plants and trees give off oxygen, and certain bacteria release methane. If we found an exoplanet with lots of these gases in its atmosphere, it could be a clue that life is at work!


There’s also something called techno-signatures. Imagine that an alien civilization is out there and is advanced enough to use technology. They might be sending out radio signals or using some type of technology that gives off energy we could detect. Scientists listen for these signals through the SETI program (Search for Extraterrestrial Intelligence). Imagine if one day, we picked up a radio signal from an alien civilization saying, “Hello, Earth!” Now, that would be a day for the history books!


SETI scientists use massive radio telescopes to listen for any unusual sounds or signals from space. While we haven’t picked up any alien broadcasts yet, SETI scientists continue listening just in case!


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### Part 5: What About UFOs and Alien Sightings?


Narrator:  

Alright, let’s switch gears for a second and talk about UFOs. When people hear “aliens,” they often think of UFOs — mysterious lights or flying objects seen in the sky. UFO stands for Unidentified Flying Object, and it just means something in the sky that can’t be explained right away.


In recent years, even the U.S. government has released videos of strange flying objects that pilots can’t identify. Scientists and investigators are curious about these sightings, but they also believe many of them could be things like weather balloons, drones, or even strange clouds.


However, the mystery of UFOs does keep people excited and asking questions, which is important in science. Even though there’s no proof yet that these UFOs are alien spaceships, some scientists believe keeping an open mind is key. After all, exploring the unknown is what science is all about!


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### Part 6: What Would Aliens Look Like?


Narrator:  

Now, let’s imagine for a moment — what if aliens do exist? What would they look like? This is one of the most fun parts of the search for extraterrestrial life because we can let our imaginations run wild.


Aliens could look like anything, depending on where they evolved. On Earth, animals look different based on where they live. Fish have gills to breathe underwater, birds have wings to fly, and polar bears have thick fur to stay warm. Similarly, aliens would be adapted to their planet’s environment. If they lived on a planet with less light, maybe they’d have huge eyes to see better. Or if they lived on a gas planet, they might float in the clouds with wings or even balloons.


Some scientists even think that aliens might not look like animals at all. They could be more like plants, using sunlight to get energy. Or they could look like giant microbes or crystals that survive on chemicals in their environment. The possibilities are endless, and this is part of what makes the search for alien life so exciting!


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### Part 7: Tools to Search for Aliens and Exoplanets


Narrator:  

Finding exoplanets and signs of life wouldn’t be possible without amazing technology! One of the most important tools for exploring space is the Hubble Space Telescope, which has been sending back incredible pictures of space since 1990. With Hubble, scientists have been able to see deep into our universe, spotting galaxies, nebulae, and exoplanets.


In 2021, the James Webb Space Telescope was launched, bringing even more powerful technology. James Webb can detect infrared light, which helps astronomers study exoplanets’ atmospheres. By studying light from distant planets, scientists can analyze the gases and particles in their atmospheres, looking for bio-signatures and other clues.


Another important tool is radio telescopes, which look for techno-signatures. Radio telescopes are like giant ears that can “listen” to signals from space. Scientists use radio telescopes to listen for any signals that might come from intelligent alien civilizations.


While we haven’t yet found any definite signals from alien civilizations, the search itself is inspiring. It’s like the ultimate treasure hunt — and every time scientists tune in, there’s a chance, however small, that we might hear a message from another world.


In addition to radio telescopes, we also have planet-hunting missions like NASA’s TESS (Transiting Exoplanet Survey Satellite) and Kepler missions, which have given us detailed information on thousands of exoplanets. TESS, launched in 2018, has a big mission: to scan nearly the entire sky, looking for planets orbiting stars close to our solar system. By doing this, TESS has identified many potentially habitable exoplanets and continues to uncover fascinating new worlds.


Another exciting mission is Gaia, a spacecraft launched by the European Space Agency. Gaia creates an incredibly detailed map of our galaxy, the Milky Way, by tracking the positions, distances, and motions of stars. This map helps scientists understand which stars are most likely to host planets and even gives clues to the birth and evolution of stars and planets throughout the galaxy.


And just wait — in the coming years, there are plans for even more advanced missions. LUVOIR (Large UV Optical Infrared Surveyor) is a proposed mission that would combine multiple space telescopes into one, allowing scientists to detect smaller, Earth-sized exoplanets orbiting other stars. If LUVOIR or another future telescope finds an exoplanet with a similar atmosphere to Earth, it could be a giant leap forward in the search for life.


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### Part 8: Could Humans Ever Travel to Exoplanets?


Narrator:  

Alright, now let’s get into something super exciting to imagine — could we, one day, travel to these distant planets ourselves? Right now, the nearest star system with known exoplanets is Alpha Centauri, which is about 4.37 light-years away. To give you an idea of how far that is, if we were traveling at the speed of the fastest spacecraft humans have built, it would still take us thousands of years to reach Alpha Centauri!


But don’t worry, scientists are working on new ideas to help us get there faster. One concept is called light sails. Imagine a spacecraft with a sail, but instead of using wind to move, it’s pushed by beams of light from powerful lasers. This idea is called the Breakthrough Starshot Initiative, and it’s led by some of the world’s most brilliant scientists. They hope to create a fleet of tiny, lightweight probes that could travel to Alpha Centauri at 20% of the speed of light. At that speed, the probes could reach the nearest stars in about 20 years!


Another concept for interstellar travel involves nuclear fusion, a process that could potentially release enough energy to power a spacecraft through deep space. Fusion is what powers our Sun, and if scientists can create a safe and powerful fusion engine, it could make interstellar travel much more realistic. Who knows? In the future, we might even build a ship that can go to distant star systems to explore exoplanets in person!


While it might take many generations, these bold plans could pave the way for future human explorers to travel to distant worlds. And if that happens, who knows what they might find?


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### Part 9: Why Does the Search for Aliens and Exoplanets Matter?


Narrator:  

So, you might be wondering, “Why are we spending so much time and effort looking for aliens and exoplanets?” Well, the search for life beyond Earth helps us learn more about our own planet and our place in the universe. It also teaches us how precious and unique Earth is, which is important for taking care of our home.


For instance, by studying other planets’ atmospheres, scientists learn more about how climates work, which helps us understand and tackle climate change here on Earth. Observing planets that are too hot, too cold, or have runaway greenhouse gases teaches us what might happen if Earth’s climate were to shift too much in any one direction.


Another reason we search for aliens and exoplanets is simply curiosity. Humans have always wanted to explore and discover new things. It’s the same reason people once sailed across oceans and climbed mountains. We have an incredible desire to know what’s out there, and the universe is the biggest “out there” there is! Who knows what amazing discoveries are still waiting to be found?


Finally, the search for life elsewhere is inspiring. When we look up at the stars, we’re reminded that we’re part of something much bigger than ourselves. Whether or not we find aliens, the search helps us answer one of the oldest questions: Are we alone?


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### Part 10: Imagine the Future — Living on Exoplanets


Narrator:  

Let’s imagine, for a second, that one day we do find a habitable exoplanet — a new “Earth 2.0.” What if humans could actually move there and start a new life? If technology continues to advance, future generations might develop ways to travel to and settle on distant planets.


Living on an exoplanet would be an adventure, to say the least! There could be challenges, like different gravity, strange atmospheres, or unknown creatures. Humans would need special equipment, like spacesuits and shelters, to survive at first. Scientists might even need to “terraform” the planet — a process of making the environment more Earth-like, so plants, animals, and humans could survive more easily.


Just think of it: Kids in the future might go to school on a different planet, looking up at two or three suns in the sky instead of one! They might explore forests of alien plants or learn to live with new creatures we can’t even imagine yet. It would be like living in a science fiction story — only real!


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### Outro: What’s Next in the Search?


Narrator:  

That’s it for today’s journey through the stars, but the search for exoplanets and alien life is only just beginning. Scientists are discovering new exoplanets every month, and with each new world, we get a little closer to answering the big question: Are we alone in the universe?


So, whether you dream of discovering alien life, exploring far-off planets, or simply looking up at the stars, remember that science and curiosity are the keys to making these dreams a reality. Who knows? One of you listening might even be the scientist who finds life on another planet one day!


Thank you for joining me on this adventure! If you have any questions or ideas for future episodes, ask your parents to help you send us a message. And don’t forget to look up at the night sky tonight — who knows what’s out there, just waiting to be discovered?


Outro Music Plays


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End of Episode



Nov 20, 2024

10 min read

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