Thud! The small silver rocket with a red nose landed on the grass. Leo sighed and picked it up. It was his third attempt, and his best creation of cardboard and tape had never made it higher than the branches of the old apple tree.
"It fell again," he frowned, showing the rocket to his friend Mia, who was diligently drawing everything in her notebook.
"Third attempt: unsuccessful," Mia noted, drawing a sad rocket lying on the ground. "But why does everything fall anyway? Why doesn't it just fly away?"
A cheerful laugh came from the bench under the apple tree. It was Grandpa Vlad, who was watching them with a smile. "That was just Mrs. Gravity saying hello," he said, winking at them.
Leo and Mia ran over to him curiously. "Mrs. Gravity? Who's that?" Leo asked. He had never heard of her. Does she live in their town?
"Oh, she's everywhere," Grandpa laughed. "She's an invisible, but very strong lady. She is very fond of all of us, so she holds us tightly to keep us from flying off into space. You can feel her hug everywhere. When you jump, she pulls you back to the ground. When an apple falls from your hand, she makes sure it lands on the ground and not on the roof of a house."
Mia immediately drew a big, smiling planet Earth in her notebook with arrows pointing towards its center. "So she's actually protecting us?"
"Exactly! Without her, we, houses, cars, and even the water in the rivers would all float away," explained Grandpa Vlad.
Leo thought for a moment. He looked at his little rocket. "So my rocket can't take off because Mrs. Gravity is holding it too tightly?"
"That's exactly right," Grandpa nodded. "Her hug is strongest near the ground."
"Aha!" Mia exclaimed. "Let's do an experiment! What if something is lighter? Will she hold it less tightly?" She plucked a small feather from a nearby bush and picked up a little stone in her other hand. "What do you think will fall faster?"
"The stone is heavier, it'll fall right away!" Leo blurted out.
Mia let go of both things at the same time. The stone plummeted to the ground without hesitation. Splash! It landed right in a puddle. But the feather? It floated slowly, dancing in the air, as if it were playing a game of tag with Mrs. Gravity. Finally, it drifted gently down onto the grass.
"See?" said Grandpa Vlad. "Mrs. Gravity pulls them both equally, but the air keeps the feather from falling freely. It's like swimming in water; you're slower then, too. But in the end, she pulls everything down to the ground."
"So we need something very, very strong to escape her hug," Leo pondered, looking at the sky. "Something stronger than my arms when I throw the rocket."
"Exactly! And that's what scientists figured out," Grandpa continued, his eyes sparkling. "They invented real rockets. They have huge engines at the bottom. When they turn on, they create so much force that they literally push the rocket away from the Earth. It's like pushing off the ground with your feet to jump, only a million times stronger."
Grandpa took out his phone and showed them a video of a real rocket launch. Huge flames and thick smoke shot out from its bottom. The rocket slowly lifted off and, with a tremendous roar, flew higher and higher until it became just a tiny dot in the blue sky.
"Wow!" the children breathed at once.
"And what happens then? When the rocket gets really far away?" Mia asked curiously.
"Excellent question!" Grandpa praised her. "Imagine Mrs. Gravity is calling to you from your house. The farther away you get, the more faintly you hear her, right? It's the same with her hug. The farther an astronaut in a rocket gets from Earth, the weaker her hug becomes."
He showed them another picture. It was of an astronaut floating inside a space station. His hair was sticking up funnily in all directions, and an apple was floating next to him.
"Wow! He's flying!" Leo shouted. "So Mrs. Gravity can't reach him there?"
"Almost," Grandpa smiled. "She still holds him a little bit, so he doesn't fly away completely, but her hug is so weak that it can't keep him on the floor. We call this state weightlessness. Everything that isn't tied down floats freely. Astronauts, their food, pencils, drops of water..."
Mia quickly drew an astronaut trying to catch a floating strawberry. "That must be fun!"
"It sure is," Grandpa agreed. "But it's also challenging. Imagine trying to brush your teeth and the toothpaste floats off your brush. Or you want to take a drink and the water breaks into a thousand little balls."
Leo laughed at the thought. He picked up his cardboard rocket. "So you just need a stronger engine," he said to it seriously. "So you can overcome Mrs. Gravity's hug and go see how apples float."
Then he turned to his grandpa. "And does the astronaut come back afterwards?"
"Of course. When the spaceship starts to return to Earth, Mrs. Gravity catches him in her strong hug again and pulls him nicely back home. And when he lands, he'll once again feel how firmly he is standing on the ground."
Leo and Mia looked down at their feet. They were standing firmly on the grass. Leo jumped and landed right back down. He laughed.
"Thank you, Mrs. Gravity!" he shouted cheerfully towards the sky. "It's great that you're holding on to us!"
On the last page of her notebook, Mia wrote in big letters: CONCLUSION: MRS. GRAVITY IS OUR FRIEND. And underneath, she drew a smiling Earth hugging two little figures.
"What do you think, kids," Grandpa Vlad asked finally, "if you were to fly into space, where everything floats, what one thing would you take with you and why?"
Leo and Mia looked at each other. That was a great question to think about. And maybe for building a new, even better rocket.