Book 23, Question 83
Why Does a Weather Balloon Swell as It Rises, and Then Pop?
A weather balloon starts small. As it rises, it swells. Then it pops! Weather balloons are launched twice a day from sites all over the world.
More fun facts
- A weather balloon is filled with hydrogen or helium and rises about 1,000 feet every minute.
- Because the air pressure around it drops as it climbs, the balloon keeps expanding.
- At launch, it's about 5 feet wide, but by 100,000 feet it's as tall as a two story building.
- Up high, the air pressure is less than 1 percent of the pressure at the ground.
- When the balloon stretches past its limit, it pops.
Questions kids ask
Do people find the fallen instruments?
Only about 20 percent of the roughly 75,000 radiosondes launched each year are found and sent back to be fixed and used again.