These cosmic outliers are so strange that astronomers aren’t sure how they formed. Comets are more fragile than they appear and are easily shattered by cosmic collisions or by straying too close to massive bodies. During their first viewing, astronomers observed a dense cloud of gas emanating from the restless baby star. In January 2015, humanity’s stalwart observer Hubble caught a trio of Galilean satellites—Io, Europa, and Callisto—lined up in front of their gas giant daddy. But a recent, incredibly rare celestial object has been discovered—a pre-natal globular cluster, full of gas but lacking in stars.