Balloon release

A balloon release is a ceremonial event in which a number of hydrogen or helium-filled balloons are unleashed into the sky.

Balloon releases can be done as a prayer ceremony, to create a photo opportunity, to raise awareness of a cause or campaign, or as a competitive long-distance race. There is considerable opposition to, and legislation against, balloon releases, due to environmental, flight safety, and wildlife conservation issues.

Massive balloon releases gained popularity during the 1980s, and fell out of popularity following research on the biopersistence, distance-travelled, and gastronomical effect on animals.

Akin to a Sky lantern ceremony of Chinese tradition, a group balloon release can serve as a quiet, prayerful group activity at a funeral or solemn occasion. Unlike sky lanterns, which float down after a short time, helium or hydrogen balloons quickly rise to heights in which they can no longer be seen. Balloon releases are also used in celebration, as a substitute to confetti, in order to avoid an immediate mess.

A balloon race or balloon flight contest is a competition wherein the competitors attempt to send balloons as far as possible. It can be compared to a rubber duck race. Postcards are attached to the balloons which are then released. The flight of the balloons cannot be influenced by the competitors. Instead, success in the contest is dependent on the wind conditions and on the location in which the balloon lands. The contest depends on the goodwill of passers-by to find the balloons and return the postcards. A prize may be awarded to the person whose balloon travels the furthest.

Helium balloons are claimed to reach a height of anywhere up to ten kilometres. At such heights, atmospheric pressure is dramatically reduced, so a helium balloon expands as it rises. With temperatures so low, the balloon material is also expected to freeze. Eventually as the material is stretched too thin, the balloon is likely to pop suddenly. An estimated 90-95% of released balloons rise to an altitude of 5 miles where the temperature and pressure is such that they burst into small fragments.

It is also possible for a balloon, under the right circumstances, to reach equilibrium, and remain suspended in the air for some time, until the helium slowly diffuses out of the balloon.

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Wikipedia