What happens when a helium-filled balloon is released and rises into the atmosphere? How long does a balloon last in the sky? Well, let’s see. As it gets higher, the temperature and pressure around the balloon begin to fall. But the pressure inside stays the same, which makes the balloon constantly expand. It travels upwards for about an hour and a half, and reaches a height of about 28,000 feet, or 5 miles. That’s only a little less than the altitude that planes fly at. That’s when it goes pop, and the little pieces fall all the way back to the ground.  

The Balloonfest ’86 was a fundraising event that took place in the city of Cleveland, Ohio. The goal was to set a new world record by releasing a huge number of balloons into the air. They wanted to release 2 million of them, and it took 6 months to organize. Just as it started to rain in the early afternoon, the balloons were released into the grey sky, setting a new world record. The colorful cloud filled the square. But as the rain became heavier, the balloons were pushed back down. The storm carried them back to the city...

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