This planet-like balloon started out as two elastomer sheets, heat-sealed together into a spiraling tube. As the balloon was inflated, it changed from flat to a saddle-like shape. With more air, the pressure inside increased, triggering an instability that caused the middle of the balloon to bulge. As inflation continued, the central bulge expanded, unbonding layer after layer of the seal. Even late in inflation, the balloon maintains hints of its original shape in the form of a ring around the Jovian bulge in the middle. (Image credit: N. Vani et al.)
“Bulging Balloons”
