Cloudy Findings: A new population shows up in the Milky Way

A radio telescope has detected hundreds of hydrogen clouds in the gaseous halo that surrounds the disk of our galaxy. This previously unknown population may have been lofted into the halo by a galactic fountain–powerful winds from supernova explosions within the disk.

CLOUD CROWD. An artist’s rendition of an edge-on view of the Milky Way (middle and left) shows hundreds of hydrogen clouds floating above the disk of the galaxy, some 15,000 light-years from Earth.