Massive star clusters can pop into existence in a matter of a few million years, a very short period of time on astronomical time scales.  They consist of hundreds or thousands of massive, bright, hot stars that will live relatively short lives of a few hundred millions of years.  Using the Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have discovered a vanishingly rare molecular cloud of highly dense gas, containing no stars.  It is poised to become a massive star cluster, and we found it in its infancy. “We may be witnessing one of the most ancient and extreme modes of...