Why Does a Weather Balloon Swell as It Rises, and Then Pop?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why does a weather balloon swell as it rises, and then pop?

The Big Idea

A weather balloon starts small. As it rises, it swells. Then it pops!

Starts Small

Step one: starts small. A weather balloon starts about as tall as a person, partly filled with gas. Then it begins to rise.

Swells Up

Step two: swells up. As it rises, the air around it gets thinner and the pressure drops. So the gas inside expands and the balloon stretches bigger.

Pop and Drift Down

Step three: pop and drift down. At about one hundred thousand feet, the balloon is the size of a house and finally bursts. A small parachute brings its instrument package, called a radiosonde, back down.

A Closer Look

Let's take a closer look! The balloon starts small. It grows as it rises. At the top it pops. A parachute brings the gear down.

Quick Facts

Quick facts! Weather balloons are launched twice a day from sites all over the world. A parachute brings the gear down. The radiosonde measures the air. At the top the balloon is as big as a house.

Think Like a Scientist

Now, think like a scientist! Draw a small balloon at the ground. Draw a huge one high in the sky. Add arrows to show the gas pushing out. Label the thin air up high. Then tell a friend what you found out.

Outro

A weather balloon swells as it rises because the air gets thinner, until it pops and a small parachute brings its instruments down. Science is amazing! Stay curious! Share what you learned with someone at home, and see what they think! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!