Massive stars — those at least 8 times the mass of our Sun — present an intriguing mystery: how do they grow so large when the vast majority of stars in the Milky Way are considerably smaller? Massive stars — those at least 8 times the mass of our Sun — present an intriguing mystery: how do they grow so large when the vast majority of stars in the Milky Way are considerably smaller? To find the answer, astronomers used the Atacama Large Millimeter/submillimeter Array telescope to survey the cores of some of the darkest, coldest, and densest clouds in our Galaxy to search for the telltale signs of star formation.