Why do Planets have Orbits?

0:00And now it's time for who's smarted. Hey smarty pants, I'm sure you recognize these sounds. Yep, I'm back at the amusement park. I just can't get enough roller coasters. Water rides. Thrilling drop rides. And of course rides that's been around and around and around. Mr, if you're looking for the merry-go-round, you're in the wrong line. Nope, my bubblegum chewing bubble-blowing friend. While the merry-go-round is fun, I'm here for the swing ride. You know, the one where you sit on chairs that zip around, high in the air, as if orbiting a pedestal. Yeah, I work here. Yes, I know you know, but never mind. Smarty pants, are you fans of rides that go around and around? If so, you're in for a treat. And if you're not, I have some interesting news to share with you. Six credits. Excuse me? You need six credits to ride. You going on or not?

1:01Yes, but first, I need to let the smarty pants know that, whether you like it or not, you're already on a spinning ride that goes around and around. Do you know what ride that is? You got the six credits or what? Wow, you are really good at blowing bubbles and interrupting. Here, here's my wristband. Enjoy the ride. So, smarty pants, what spinning ride are you on right now, even if you think you're standing still? Did you say the ride known as Planet Earth? That's right. And do you know how fast you're spinning right now? Is it up to A 42 miles an hour? B, 340 miles an hour. Or C, 1000 miles an hour. Well, hold on to your hats because the answer is Z. All times, you are moving up to 1000 miles or about 1700 kilometers an hour. Whoa. Oh, and that's not all. Sir, you're holding up the line.

2:01I'm going, I'm going. Buckle up. Don't throw anything. Gotcha. As I was saying, smarty pants, that's not all. As you probably know, Earth orbits the sun. But did you know Earth orbits the sun at a speed faster than its rotation? About 67 times faster, in fact. At that speed, you'd be able to fly from New York to London in about three minutes. Yeah, this ride doesn't go that fast. You don't understand. Right now, we're all going that fast. Whatever. Hold on to your hat. So, smarty pants, how do orbits work? How did they form? And could the planets ever crush into each other? Or the sun? Whoa. It's time for another big wave of science, son. Hello, smart egg. Who smarted? Who smart is it you?

3:01Is it me? Is it science? Or history? Listen up. Everyone, we make smarting lots of fun. Hello, smart egg. Hey, smarty pants. Did you know that some rides at amusement parks are just like the planetary orbits? They go around and around a central point. Huh. And just think, as you go around here, Earth is going around the sun. While the sun is going around the center of our galaxy, the Milky Way. Huh. Smarty pants. Do you know what is at that center of the Milky Way? Is it a giant star? B, a black hole. Or C, delicious chocolate nougat and caramel. Why it's C, of course, if you're talking about a Milky Way candy bar, but the center of the Milky Way galaxy is B, a black hole. Whoa. The sun and the whole solar system moves around this black hole at around 447,000 miles per hour or 200 kilometers per second.

4:02That's over 100 times faster than the world's fastest plane. And even at that super fast speed, do you know how long it takes the solar system to orbit the Milky Way center up to 500 days, up to 3,000 years, or up to 250 million years? The answer is 220 to 250 million years! Of course, it doesn't take that long for the Earth to orbit the sun. I know you know that number. Go ahead, shout it out. Yep, compared to the galaxy, the 365 days it takes Earth to orbit the sun seems like nothing. And I'm sure you also know there are seven other planets, numerous dwarf planets, asteroids, and other objects orbiting the sun too. And for the most part, they don't bump into each other. Ah, unlike the people on this ride. Smarty pants, do you know what ride I'm on? Oh, if you said the bumper cars, you're right. Okay, rides over, everybody out.

5:04But imagine if the planets did bump around all the time, like bumper cars. Oh boy, we'd be living in constant fear that one day we'll smack into Mars, Venus, or worse, Jupiter! But here's the crazy thing. At one point in time, the objects in our solar system did collide like that. Whoa! Great, whatever. Are you planning to ride again or what? No, I think I'll grab some lunch. Smarty pants, do you know when all these collisions in our solar system took place? If so, go ahead and shout out your answer. If not, I'll tell ya. It happened back when the solar system was formed. Hello, my friend. Welcome to the best pizza parlour in the amusement park. For you, I'm gonna make a nice pepperoni pizza pie. Great. And also, that will help me demonstrate. Because in some way, Smarty pants, the solar system formed like a pizza. A pizza? Yep.

6:04Think of that clump of pizza dough you're holding, like the nebula that became our solar system. Basically, a big cloud of dust and gas. Excuse me. About 4.6 billion years ago, something happened that got that cloud in motion. Perhaps the explosion of a nearby star. Soon, the whole cloud was moving around, like pizza dough being tossed into the air. Parts of it combined, forming the sun in the middle. The rest moved faster and faster and flattened out, like pizza dough stretching as it's tossed. A thrill work of art. At this point, the matter in other parts of the cloud started to clump together and smashed into each other, just like the bumper cars. These clumps collected the matter they smashed into, becoming larger and larger, and clearing their path as they went around the center. Eventually, these clumps of matter became planets. Each swirling around with their own rotation as they continue to orbit the center. The dough is getting very big now.

7:06And all these things continued in the same direction as the original nebula, like they're still part of a twirling pizza dough. And the planets will continue to move in the same direction and distance apart from each other, as long as there's nothing to stop them. Mamma mia, I got too excited and I threw the dough onto the ceiling. It's okay, I'll just grab a slice. Good choice. You a nice man. Thanks! So, Smarty Pants, the movement of the nebula that created our solar system 4.6 billion years ago, led to the planetary movement that we have today. And all the planets are lined up with the center of the sun because that nebula flattened out just like the rotating pizza crust. In fact, all the planets move in the same direction as the sun's rotation. And they stay in their orbits because of a particular force. Any idea what that is, Smarty Pants? Is it A, gravity, B, magnetism, or C, mitochondrions?

8:11The answer is gravity. The sun's gravity pulls on the planets, but what keeps them from crashing into it? To answer that, we'll blast into space on this space-rocket ride. That'll be eight credits. Sure, scan away. How is it that you work at every ride in the park? Enjoy the ride. Wait, shouldn't I get a space suit or something? Nah, just keep your hands inside the ride at all times. Whoa! So, Smarty Pants would actually keep the planets in their orbits. We'll have that answer from space right after this quick break. Spring is here, and if you're a homeschool family trying to finish the year strong, I want to tell you about IXL. It's the award-winning online learning platform that fits seamlessly into your homeschool routine, covering math, language arts, science, and social studies from pre-K through 12th grade. What I love most about IXL is how it adapts to each child's pace.

9:15Whether your kid needs to reinforce foundational skills before an assessment or push ahead into new material, IXL meets them exactly where they are, with no pressure and real encouragement built right in. Kids earn rewards, see their own progress, and actually feel good about learning. And for parents, the real-time progress tracking is a game-changer. You always know exactly where your child stands. Plus, it makes learning fun, and you know I love that. Over 15 million students use IXL, and it's proven to improve achievement in all 50 states. So make an impact on your child's learning. Who's smarted listeners get an exclusive 20% off at IXL.com slash-smarted? That's IXL.com slash-smarted for your 20% off. Now back to who's smarted. Okay, smarty pants. We're high up in space now, looking down at the Sun's North Pole.

10:18From here, in what direction are all the planets moving? Is it in the same direction as the hands of a clock? Also known as clockwise? Or in the other direction, also known as counterclockwise? If you said counterclockwise, you're right. Now answer this, true or false? Planets in every solar system move counterclockwise. The answer is false. Some actually go clockwise. Planetary movement happens randomly depending on the force that hits the nebula that created the planets. It's the same thing with galaxies. Scientists think that half spin one way, while the other half spin in the opposite direction. If you want to visit another galaxy, it'll cost you six more credits. No, that's not what we're... Hey, what are you doing here? What does it look like I'm doing? Working. Anyway, smarty pants. If the planets in our solar system are being pulled by the Sun's gravity, what's keeping them from crashing into the Sun? I don't know how the rides work. I just push the button.

11:20Smarty pants, consider this. The fastest moving planet, Mercury, is closest to the Sun. While the slowest moving one, Neptune, is farthest away. Did you say the speed of the planet is what keeps it from crashing into the Sun? If so, nice job. If a planet's forward momentum was too small, the Sun's gravity would pull it in. But if its momentum was too great, it would go flying off, never to be seen again. Mercury experiences a tremendous amount of the Sun's gravity, so it needs to move fast. While Neptune, billions of kilometers away, doesn't require as much momentum. Everything is in balance, so the planets stay in orbit, and will continue to do so until hit by an outside force, like a star exploding. But don't worry, that shouldn't happen in your lifetime. Great, so the planets will just keep spinning around in circles, like my life. Well, that's not exactly true. Huh? Are you saying my life isn't spinning in circles?

12:22No, I'm saying the planets don't move in circles. Smarty pants, what shape is a planetary orbit? Is it A, square, B, oval, or C, a regular? The answer is B, oval. Even though the planetary orbits are almost circular, they're actually elliptical, which means they're like ovals. Fine, my life is going around and around like ovals. But get this, at some point, a planet is closer to the Sun than at other points. When do you think Earth is closest to the Sun? Is it summertime in the Northern Hemisphere, summertime in the Southern Hemisphere, or during the March Equinox? The answer is, during summertime in the Southern Hemisphere, it's actually at its farthest point from the Sun during summertime in the Northern Hemisphere, and speaking of the Northern Hemisphere, it's about time I get back there. It'll be eight more credits. What? I have to pay to get back? You did say Earth is a ride, right? Yeah, but eight credits.

13:23Fine. Besides, Earth is the best ride on the planet. Buckle up, enjoy the ride. A cosmic shout out to George in Saskatchewan, Canada. Thanks for letting us know how much you love learning about science and history, and that you think who smarted makes learning fun for everyone. Even mom and dad. Keep on smarting with us, Smarty Pants. This episode, Planetary Orbits, was written by Dave Bojri, and voiced by Olivia Davis, Max Kamaski, and Jerry Colbert, technical direction and sound designed by Josh Hahn, who smarted as recorded and mixed at the Relic Room Studios. Our associate producer is Max Kamaski. The theme song is by Brian Suarez, with lyrics written and performed by Adam Text Davis, who smarted was created and produced by Adam Text Davis and Jerry Colbert. This has been an atomic entertainment production.