# What is an asteroid?

An episode of [Science for Kids / Science's Not Boring: The Kids Science Podcast](https://invisiblenetwork.ai/podcast/1896928296), 30 Jun 2026, 14 min.

Audio: https://www.buzzsprout.com/2624612/episodes/19406108-what-is-an-asteroid.mp3

Have you ever wondered what happens to the leftover cosmic crumbs in outer space? Welcome to the wild world of asteroids and comets! Join Mira and Finn on an incredible journey to discover the giant space rocks whizzing around our Sun. You will learn all about asteroids, which are massive chunks of rock and metal that look like giant floating potatoes, and comets, which are dirty snowballs that grow spectacular, glowing tails millions of miles long! We are diving deep into some of the biggest space mysteries in Earth's history. Discover the massive six-mile-wide rock that crashed into Earth and helped wipe out the dinosaurs millions of years ago. Then, uncover the shocking secret of the 1908 Tunguska explosion in Russia, where a giant rock exploded in the sky and flattened 80 million trees without leaving a single crater! Plus, find out how scientists are acting as Earth's very own space security guards by practicing how to smash spaceships into asteroids to keep our planet safe. Get ready for a mind-blowing, out-of-this-world adventure!

## Transcript

[0:46] SPEAKER_00: Welcome to Science Is Not Boring by kidopoly.com.
[0:50] SPEAKER_00: I'm Mira! And I'm Finn.
[0:53] SPEAKER_00: Finn, imagine waking up, sipping your hot cocoa, and suddenly the sky lights up with a flash brighter than the sun.
[1:02] SPEAKER_00: Whoa! Brighter than the sun?
[1:05] SPEAKER_00: What is it?
[1:06] SPEAKER_00: You look out the window and a massive boom shakes the ground, flattening 80 million trees in an instant.
[1:14] SPEAKER_00: 80 million trees?
[1:16] SPEAKER_00: Was it a giant volcano?
[1:18] SPEAKER_00: A massive earthquake?
[1:20] SPEAKER_00: Nope, it was a giant rock from outer space, travelling thousands of miles an hour.
[1:25] SPEAKER_00: But here is the wildest part.
[1:28] SPEAKER_00: When scientists searched the forest, they found absolutely no crater.
[1:32] SPEAKER_01: Wait, wait.
[1:34] SPEAKER_01: A giant space rock knocked down a whole forest but didn't leave a hole in the ground.
[1:39] SPEAKER_01: How is that even possible?
[1:41] SPEAKER_00: That is exactly what we are exploring today.
[1:44] SPEAKER_00: We are diving deep into the mysteries of asteroids, comets, and the giant space rocks whizzing around our Sun.
[1:51] SPEAKER_01: Wait, should we be worried about one hitting Earth right now?
[1:54] SPEAKER_00: Not at all.
[1:56] SPEAKER_00: Big impacts are extremely rare.
[1:58] SPEAKER_00: Today, you're going to learn how scientists watch the skies every single night to keep our beautiful planet safe.
[2:05] SPEAKER_01: Oh few.
[2:06] SPEAKER_01: Like Earth's very own space security guards.
[2:09] SPEAKER_01: I love this already.
[2:11] SPEAKER_01: Let's go.
[2:11] SPEAKER_00: Let's start with the basics.
[2:13] SPEAKER_00: Space is actually full of leftovers.
[2:16] SPEAKER_00: When our solar system formed about 4.6 billion years ago, not all the dust and gas made it into planets.
[2:24] SPEAKER_01: So there are just pieces floating around like cosmic crumbs.
[2:29] SPEAKER_00: Exactly! Cosmic crumbs! And there are two main types of crumbs we talk about: asteroids and comets.
[2:38] SPEAKER_00: Let's do asteroids first.
[2:40] SPEAKER_01: I've seen them in movies.
[2:41] SPEAKER_01: They look like giant floating burnt potatoes covered in holes.
[2:46] SPEAKER_00: That's a perfect description.
[2:48] SPEAKER_00: Asteroids are solid chunks of rock and metal.
[2:51] SPEAKER_00: Millions of them live in the asteroid belt, a huge ring hanging out between the planets Mars and Jupiter.
[2:58] SPEAKER_00: How big are they?
[3:00] SPEAKER_00: Like the size of a car?
[3:01] SPEAKER_00: They range in size.
[3:03] SPEAKER_00: Some are tiny pebbles, but the biggest one, named Ceres, is almost 600 miles wide.
[3:10] SPEAKER_00: That's as wide as the entire state of Texas.
[3:14] SPEAKER_01: Texas floating in space! Okay, so what about comets?
[3:19] SPEAKER_01: Are they just icy potatoes?
[3:22] SPEAKER_00: Pretty much.
[3:23] SPEAKER_00: Scientists often call comets dirty snowballs.
[3:26] SPEAKER_00: They are made of ice, dust, and frozen gases.
[3:30] SPEAKER_01: Where do the snowballs come from?
[3:32] SPEAKER_01: Is there a giant freezer out in space?
[3:35] SPEAKER_00: Sort of.
[3:36] SPEAKER_00: They come from the freezing cold, dark edges of our solar system, way past Pluto, in mysterious places called the Kuiper Belt and the Oort Cloud.
[3:46] SPEAKER_01: Wait, I know a cool fact about comets.
[3:49] SPEAKER_01: They have those long glowing tails, right?
[3:52] SPEAKER_01: Yes.
[3:53] SPEAKER_00: When a comet's orbit swings it close to the sun, it heats up.
[3:57] SPEAKER_00: But instead of melting, the ice sublimates.
[4:01] SPEAKER_00: It turns directly into gas, blowing backward to make a beautiful glowing tail.
[4:06] SPEAKER_00: How long is the tail?
[4:08] SPEAKER_00: Like a few miles?
[4:10] SPEAKER_00: Way bigger.
[4:11] SPEAKER_00: It can be millions of miles long.
[4:13] SPEAKER_00: You could stretch a comet's tail from the Earth all the way to the Sun and back.
[4:18] SPEAKER_01: Whoa, a tail big enough to touch the Sun?
[4:22] SPEAKER_01: That is spectacular.
[4:24] SPEAKER_00: It is beautiful.
[4:25] SPEAKER_00: But sometimes these space rocks wander off their normal paths and cross orbits with Earth.
[4:31] SPEAKER_01: Uh-oh, that sounds like a cosmic traffic accident waiting to happen.
[4:36] SPEAKER_00: It has happened.
[4:38] SPEAKER_00: The most famous traffic accident was 66 million years ago.
[4:42] SPEAKER_00: A massive asteroid crashed into Earth and helped wipe out the dinosaurs.
[4:47] SPEAKER_01: Wait, how big was the dinosaur asteroid?
[4:50] SPEAKER_01: Was it Texas-sized, like Ceres?
[4:53] SPEAKER_00: No, it was about six miles wide.
[4:56] SPEAKER_00: Imagine a solid rock taller than Mount Everest, falling from the sky.
[5:02] SPEAKER_00: Six miles taller than a mountain?
[5:05] SPEAKER_00: How fast was it going?
[5:06] SPEAKER_00: Try 45,000 miles per hour.
[5:10] SPEAKER_00: It was zooming so fast it could cross the entire United States in just a few minutes.
[5:16] SPEAKER_00: It burned brighter than the sun as it ripped through the sky.
[5:19] SPEAKER_00: Whoosh! Boom! Where exactly did it hit?
[5:24] SPEAKER_00: It slammed into a shallow sea in what is now the Yucatan Peninsula in Mexico.
[5:29] SPEAKER_00: The crash created a giant crater named Chickselub.
[5:33] SPEAKER_00: Chicksalub?
[5:34] SPEAKER_00: How big is the crater?
[5:36] SPEAKER_01: Could a city fit inside it?
[5:38] SPEAKER_00: A whole state could! The crater is 93 miles wide and 12 miles deep.
[5:44] SPEAKER_00: The impact caused giant tsunamis, earthquakes, and kicked up so much dust it blocked out the sun for years.
[5:52] SPEAKER_01: Oh no.
[5:53] SPEAKER_01: Without the sun, the plants couldn't grow.
[5:56] SPEAKER_01: And the plant-eating dinosaurs got hungry.
[5:59] SPEAKER_00: Exactly.
[6:00] SPEAKER_00: And then the meat-eaters got hungry too.
[6:03] SPEAKER_00: The cold and the darkness changed the whole planet, bringing the incredible age of the dinosaurs to an end.
[6:09] SPEAKER_01: Well, I love T-Rexes, but I'm kind of glad they aren't roaming around today.
[6:15] SPEAKER_00: Me too! But that was a very, very long time ago.
[6:19] SPEAKER_00: Huge strikes like that are incredibly rare.
[6:22] SPEAKER_00: But what about smaller rocks?
[6:24] SPEAKER_00: Do they ever hit us?
[6:25] SPEAKER_00: They do.
[6:26] SPEAKER_00: Tons of harmless space dust falls on Earth every single day.
[6:30] SPEAKER_00: But to find a really crazy mystery about a bigger rock, we have to travel to the year 1908.
[6:36] SPEAKER_00: Fast forward to the morning of June 30, 1908, in a remote wild forest in Siberia, Russia.
[6:44] SPEAKER_01: Siberia?
[6:45] SPEAKER_01: That's really far up north, right?
[6:48] SPEAKER_01: Lots of trees and snow?
[6:50] SPEAKER_00: Exactly.
[6:51] SPEAKER_00: Millions of pine trees and frozen swamps.
[6:54] SPEAKER_00: Suddenly, the sky split in two.
[6:57] SPEAKER_00: A flash brighter than the sun lit up the morning.
[7:01] SPEAKER_00: What was it?
[7:02] SPEAKER_00: Was it a comet?
[7:03] SPEAKER_00: It was a giant space rock, probably about 160 feet wide.
[7:09] SPEAKER_00: That is the size of a 15-story office building falling from space.
[7:14] SPEAKER_01: Did it smash into the ground and make a giant crater like the dinosaur one?
[7:19] SPEAKER_00: That is the wildest part of the mystery fin.
[7:21] SPEAKER_00: It never hit the ground.
[7:23] SPEAKER_00: It exploded in the air, about three to six miles up in the sky.
[7:28] SPEAKER_01: Wait, wait, it exploded in the sky?
[7:31] SPEAKER_01: How does a rock explode without hitting anything?
[7:34] SPEAKER_01: It's called an airburst.
[7:35] SPEAKER_00: The rock was moving incredibly fast.
[7:38] SPEAKER_00: Hitting Earth's thick atmosphere created so much friction and pressure that the rock literally could not hold itself together and it blew up.
[7:47] SPEAKER_00: Whoa!
[7:48] SPEAKER_01: But if it exploded miles up in the sky, did it still do any damage on the ground?
[7:53] SPEAKER_00: Oh yes.
[7:54] SPEAKER_00: The explosion released the explosive force of millions of tons of dynamite.
[7:59] SPEAKER_00: A massive shockwave of heat and wind rushed down and flattened 80 million trees.
[8:08] SPEAKER_01: That is a whole forest wiped out in a single second.
[8:11] SPEAKER_00: It knocked them all over like little wooden matchsticks.
[8:14] SPEAKER_00: But it was incredibly lucky that it happened in such an empty wilderness.
[8:19] SPEAKER_00: Hardly anyone was nearby.
[8:21] SPEAKER_01: So how did scientists figure out what happened if no one was there to see it hit?
[8:26] SPEAKER_00: 19 years later, in 1927, a brave Russian scientist named Leonid Kulik led an expedition.
[8:34] SPEAKER_00: He trudged through freezing swamps for weeks just to reach the centre of the blast.
[8:39] SPEAKER_01: Did he find a giant hole?
[8:41] SPEAKER_00: Nope.
[8:42] SPEAKER_00: He found all those millions of trees knocked flat in a massive butterfly shape, pointing outward.
[8:48] SPEAKER_00: But there was zero crater, not even a tiny dent in the mud.
[8:53] SPEAKER_01: Because it blew up in the sky.
[8:55] SPEAKER_01: That is the craziest space mystery ever.
[8:58] SPEAKER_01: I can't believe the trees just stayed there like a giant map.
[9:02] SPEAKER_00: Exactly! And the blast sent so much glowing dust into the atmosphere that people in Europe could read a newspaper outside at midnight for days afterward.
[9:12] SPEAKER_01: That is incredible.
[9:13] SPEAKER_01: But Mira, are scientists watching out for these airburst rocks right now?
[9:17] SPEAKER_01: What if one heads our way?
[9:19] SPEAKER_00: They absolutely are, and the best news is, scientists aren't just watching them, we are actually practicing how to stop them.
[9:27] SPEAKER_00: Have you heard of NASA's DART mission?
[9:30] SPEAKER_00: DART.
[9:30] SPEAKER_00: Like the little arrows you throw at a Dartboard.
[9:33] SPEAKER_00: Exactly like that.
[9:35] SPEAKER_00: Dart stands for Double Asteroid Redirection Test.
[9:39] SPEAKER_00: In September 2022, NASA intentionally crashed a spaceship into an asteroid.
[9:45] SPEAKER_00: No way! Why would they crash a perfectly good spaceship?
[9:50] SPEAKER_00: To see if they could nudge the asteroid off its path.
[9:53] SPEAKER_00: They aimed for a little moonlet called Dimorphus, which is about 525 feet wide.
[9:59] SPEAKER_01: So it's like playing space billiards.
[10:01] SPEAKER_01: How fast was the spaceship going?
[10:04] SPEAKER_00: 14,000 miles per hour! Wham! It smacked right into Dimorphos on live video.
[10:11] SPEAKER_00: Did it work?
[10:12] SPEAKER_00: Did it move the asteroid?
[10:14] SPEAKER_00: It worked perfectly.
[10:16] SPEAKER_00: It shortened the asteroid's orbit by 33 minutes.
[10:19] SPEAKER_00: We proved that if a dangerous rock ever comes our way, humans can literally push it off course.
[10:25] SPEAKER_01: Take that, Space Rocks.
[10:27] SPEAKER_01: Humans are officially awesome.
[10:29] SPEAKER_00: We really are.
[10:30] SPEAKER_00: Okay, time for some rapid-fire fun facts.
[10:33] SPEAKER_00: Did you know there's an asteroid named Psyche that is made almost entirely of solid metal?
[10:39] SPEAKER_00: Metal?
[10:40] SPEAKER_00: Like iron and gold?
[10:42] SPEAKER_00: Yes, it's so full of valuable metals that scientists estimate it's worth quadrillions of dollars.
[10:48] SPEAKER_00: That's enough to buy a billion million toys.
[10:51] SPEAKER_00: And what about comets?
[10:53] SPEAKER_00: The most famous one is Halley's Comet.
[10:55] SPEAKER_00: It zooms past Earth every 75 to 76 years.
[11:00] SPEAKER_00: 75 years?
[11:01] SPEAKER_01: So when is the next time we can see it in the sky?
[11:04] SPEAKER_00: It will return in the year 2061.
[11:07] SPEAKER_00: You'll be able to look up and see its glowing tail for yourself.
[11:10] SPEAKER_00: Alright, Finn, it's time for the ultimate space rock quiz!
[11:15] SPEAKER_01: I am ready.
[11:16] SPEAKER_01: My brain is officially in orbit.
[11:18] SPEAKER_00: First question.
[11:19] SPEAKER_00: What are comets made of that makes them different from asteroids?
[11:27] SPEAKER_00: Next one.
[11:28] SPEAKER_00: How wide was the giant asteroid that helped wipe out the dinosaurs?
[11:35] SPEAKER_00: Question 3.
[11:37] SPEAKER_00: In what part of Russia did the 1908 Tunguska explosion happen?
[11:45] SPEAKER_00: Here's number four.
[11:47] SPEAKER_00: What was the name of the NASA mission that successfully nudged an asteroid off course?
[11:56] SPEAKER_00: Last question.
[11:57] SPEAKER_00: Roughly how many trees were flattened in the Tunguska blast?
[12:05] SPEAKER_00: Great job! Let's see how you did.
[12:08] SPEAKER_00: The first answer is, comets are made of ice, dust and frozen gases, like dirty snowballs.
[12:15] SPEAKER_00: For question two, the dinosaur asteroid was a massive six miles wide.
[12:21] SPEAKER_00: Number three, the answer is it happened in the remote forests of Siberia.
[12:27] SPEAKER_00: For question four, the mission was called DART or the double asteroid redirection test.
[12:34] SPEAKER_00: And the final answer is an incredible 80 million trees were flattened.
[12:39] SPEAKER_00: Wow, what a massive cosmic journey we just went on!
[12:42] SPEAKER_01: I'll never look at a shooting star the same way again.
[12:46] SPEAKER_01: Knowing it's just cosmic crumbs burning up is so cool.
[12:49] SPEAKER_00: And remember, scientists are mapping the skies every single night to keep our beautiful planet perfectly safe.
[12:57] SPEAKER_01: Yeah! Earth security guards are on the job.
[13:00] SPEAKER_01: Hey, if you love learning about wild space mysteries, you should leave us a five-star review.
[13:06] SPEAKER_00: Yes! Please rate us five stars to help other kids discover the show.
[13:11] SPEAKER_00: Just scroll down in your podcast app and tap those five stars.
[13:14] SPEAKER_01: And write a review telling us if you'd rather ride a comet or an asteroid.
[13:19] SPEAKER_00: Oh, and don't forget to check out our site kidopoly.com.
[13:23] SPEAKER_00: We've got tons of amazing science activities and fun learning games waiting for you.
[13:28] SPEAKER_01: Head over to kidopoly.com to keep exploring.
[13:31] SPEAKER_01: And if you want a shout out on the show, or just want to say hi, email us at hello at kidopoly.com.
[13:38] SPEAKER_00: We love hearing from you.
[13:40] SPEAKER_01: Thanks for exploring the universe with us today.
[13:43] SPEAKER_01: See you next time on Science Is Not Boring.
[13:46] SPEAKER_00: Bye everyone.

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