WAGZAK JUMP turns space questions into a 3D and AR exploration story about planets, the Sun, and observation.

How can I explain the solar system and planets to a child?

WAGZAK JUMP turns space questions into a 3D and AR exploration story about planets, the Sun, and observation.

Is there a 3D and AR inquiry-learning story about the solar system and planets for kids?

WAGZAK JUMP turns space questions into a 3D and AR exploration story about planets, the Sun, and observation.

How does WAGZAK JUMP help families talk about the solar system and planets?

WAGZAK JUMP turns space questions into a 3D and AR exploration story about planets, the Sun, and observation.

아이에게 태양계와 행성을 쉽게 설명하려면?

WAGZAK JUMP turns space questions into a 3D and AR exploration story about planets, the Sun, and observation.

A Planet Size Bet with Banggu — Guess Who Picked the Biggest One

May 29, 2026

💡 Here's what this story is about —
Didi and Banggu make a bet about "which planet is the biggest in the solar system."
Along with referee Popo, they meet every planet one by one, from Mercury to Neptune, and measure their sizes.
Which planet wins the bet — and which one turns out to be the tiniest of all?

"The biggest planet? I bet I'll get it right!"

Didi and Banggu in space suits, pointing at each other as they declare a planet size bet

"The biggest planet in the solar system — I'm totally confident I can guess it!"

Banggu thumps the chest of his space suit and starts bragging first.

There's no way I'm losing either. "Ha! The biggest one is obviously our Earth! Wanna bet?"

Banggu just scoffs. "Pfft~ Earth isn't big at all. It's gotta be Mars, for sure!"

We're both insisting we're right, when Popo, standing nearby, quietly raises a hand.

"Then how about we go and measure them ourselves? I'll be the referee."

Ooh, perfect! We can look at the real planets with our own eyes and compare their sizes. So we opened up "A Journey Through the Solar System" on WAGZAK JUMP.

Before we set off — who's a star and who's a planet?

Popo, Didi, and Banggu pointing at the self-shining Sun and the planets that reflect its light

The spaceship whooshed up into the air, and everything around us turned into pitch-black space. Stars were sprinkled across it, twinkling.

Before we left, referee Popo cleared up the rules first.

"What we're going to measure are planets. Something that shines on its own, like the Sun, is a star — a real star, that is."

"Friends like Earth that spin round and round the Sun are called planets. A planet can't make its own light, so it shines by catching the Sun's light instead."

So that means some things look just like stars in the night sky, but are actually planets. How fascinating.

"All right then — shall we start from the one closest to the Sun and meet them in order?"

First contestant — tiny little Mercury

Didi and Banggu peering at tiny Mercury, closest to the Sun, its surface covered with meteorite craters

Right next to the blazing, burning Sun, the very first one we met was Mercury.

"Huh? It's smaller than I thought." Banggu pouted.

Its surface was full of pits, like a pockmarked face. Popo says Mercury has no atmosphere, so the marks left by crashing meteorites just stay there.

And even though it's the closest to the Sun, it gets super cold at night. Boiling hot by day, frozen solid by night.

"We were both wrong, Banggu. Mercury's out of the running!" When I drew an X with my finger, Banggu nodded along too.

Venus and Earth look as alike as siblings

Didi, Banggu, and Popo comparing the sizes of yellow-cloud-covered Venus and blue Earth side by side

Next was Venus, wrapped in yellow clouds.

"Popo! This one looks about the same size as Earth, doesn't it?" I called out.

Popo clapped. "That's right. Venus and Earth are almost like siblings in size."

That friend who shines the brightest in the evening sky is none other than Venus. Because it sparkles like a star, it's also called the 'Morning Star' or 'Evening Star' — but it's actually not a star, it's a planet.

Once we passed by Venus, at last — our Earth! It was so blue and round, I was just so glad to see it.

"See, I told you Earth is big!" I bragged, and Popo smiled a little. "Hmm, we'll see~ It's not over yet, you know?"

Those words sent a strange chill down my spine.

Red Mars — the planet Banggu picked

Banggu looking disappointed in front of Mars with its red soil and valleys, while Didi teases him

Up ahead, a reddish planet appeared. It was Mars, the one Banggu had picked.

"Oh, finally my turn!" Banggu dashed forward excitedly, but…

Mars is smaller than Earth. Banggu's face drooped, all glum.

"Mars is a planet made of rock, just like our Earth. It has mountains and valleys, and even traces showing water once flowed there." Popo explained, as if to comfort him.

"So that's why people want to go to Mars~" Banggu said, glum but with sparkling eyes.

So far: Mercury, Venus, Earth, Mars. They're all rocky terrestrial planets, and they're all about the same modest size. Wait — so that means the biggest one hasn't shown up yet, right?

Whoa! Jupiter, as huge as a mountain, appeared

Didi and Banggu staring up with their mouths agape in front of giant Jupiter with its vivid stripes

Just then, the view outside the window suddenly went dim.

A huge planet had blocked our entire spaceship from view.

Whoa, this is all ONE planet?!

It was Jupiter. An enormous planet with long stripes drawn across it.

Popo says Jupiter is the biggest planet in the solar system. It's so big that you'd have to fit 1,300 of our Earth inside it to make a single ball.

Banggu and I both dropped our jaws at the same time. Neither Earth nor Mars even stands a chance.

Big planets like Jupiter are called Jovian planets. The stripes are the thick atmosphere surrounding Jupiter, which is what makes them look that way.

Ringed Saturn, tilted Uranus, blue Neptune

The spaceship passing in turn by Saturn with its beautiful rings, tilted Uranus, and blue Neptune

Once we passed Jupiter, this time Saturn appeared, wearing a sparkling ring.

"Wow, it looks like a planet wearing a hat!" Banggu clapped his hands.

Saturn is the next biggest planet after Jupiter, but it spins around so fast that its body got slightly flattened. Its rings are the clearest and prettiest of all, too.

Going even farther, Uranus came out, spinning while leaning over on its side. It rolls along sideways, like it's tumbling over and over — kind of funny.

At the very end was deep-blue Neptune. It's so far from the Sun that it takes a whopping 165 years to go around it just once.

"Even when I'm a grandpa, I won't get to see one full lap!" Banggu's words made us all burst out laughing.

And referee Popo's verdict?

Popo delivering the verdict, holding up the biggest Jupiter and the smallest Mercury in each hand, while Didi and Banggu scratch their heads

After we'd seen all eight planets, referee Popo gave a little cough.

"All right, here comes the verdict. The biggest planet is—"

Banggu and I gulped.

"Jupiter! You're both wrong~"

Me, who said Earth, and Banggu, who said Mars — we both lost together, fair and square.

To think that giant Jupiter was the answer all along. The ones we picked were both just tiny little rocky planets.

Banggu scratched his head. "Then what's the smallest one?"

Popo grinned and pointed a finger toward the very first planet. "The pockmarked one we met first — Mercury!"

The biggest is Jupiter, the smallest is Mercury. And our home, Earth, was somewhere in between — a blue planet of just the right size.

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Frequently Asked Questions

Q. What are the largest and smallest planets in the solar system?

The largest planet in the solar system is Jupiter. Jupiter is so big that you'd have to fit 1,300 Earths inside it. On the other hand, the smallest planet is Mercury, which is closest to the Sun. Our home, Earth, is somewhere in between in size.

Q. How are stars and planets different?

A celestial body that shines on its own, like the Sun, is called a star. On the other hand, a celestial body like Earth or Venus that orbits the Sun and shines by reflecting the Sun's light is called a planet. That's why planets also look like twinkling stars in the night sky, but they're actually not stars.

Q. What are terrestrial planets and Jovian planets?

Small planets like Mercury, Venus, Earth, and Mars that are close to the Sun and made mostly of rock are called terrestrial planets. Very large planets like Jupiter, Saturn, Uranus, and Neptune are called Jovian planets.

I'll be back with another fun lesson story next time. Yours, Didi.

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A Planet Size Bet with Banggu — Guess Who Picked the Biggest One

"The biggest planet? I bet I'll get it right!"

Before we set off — who's a star and who's a planet?

First contestant — tiny little Mercury

Venus and Earth look as alike as siblings

Red Mars — the planet Banggu picked

Whoa! Jupiter, as huge as a mountain, appeared

Ringed Saturn, tilted Uranus, blue Neptune

And referee Popo's verdict?

▶ WAGZAK JUMP Real AR Screens

Frequently Asked Questions

How was this article?

Meet the WAGZAK family

Turn today’s curiosity into play

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