When I let a balloon go, how high can it go? --- Timothy, York, Pa.
Marshall Brain Answers:
The balloon will go as high as it can until it bursts. For example, this video shows a large helium balloon, partially filled at the start, that makes it 17 miles high before bursting:
It is possible to design a balloon that doesn't pop. If such a balloon were allowed to rise, it would eventually reach "the top of the atmosphere" and go no higher. Imagine that you release a balloon filled with air in the deep end of a swimming pool. The balloon will rise until it is floating on top of the water and go no higher. A balloon filled with helium would eventually get to the top of the atmosphere in that same way. It would depend on the weight of the balloon, but would be between 20 and 30 miles up.
A helium balloon from a birthday party wouldn't go that high because it is filled with helium and bursts or leaks at a much lower altitude.