On Earth, we are familiar with bubbles associated with soap or carbonated water. These bubbles consist of a thin film of liquid enclosing a volume of air or other gas that is only a few inches across.

This incredible image shows a pair of “nuclear superbubbles,” one over 4,900 light-years across and the other over 3,500 light-years. They’re emanating from the center of the galaxy NGC 3079, likely ...