Count the headlights on the highway... ✨ If you were living in this “super star” cluster, you might see a sky full of hundreds of stars, each as bright as the full moon.   This is NASAWebb’s look at Westerlund 1, one of the closest clusters of its kind. Super star clusters are young and contain more than 10,000 times the mass of the Sun packed into a small volume. Westerlund 1 is the most massive yet identified in our galaxy, with 50,000 to 100,000 times the mass of the Sun contained within a region less than six light-years across. Still considered an open cluster now, someday it will evolve into a globular cluster—a roughly spherical, tightly packed collection of old stars bound together by gravity.   Super star clusters are one of the most extreme environments in which stars and planets can form. Because our galaxy is past its peak of star formation, and because stars live relatively short lives, only a few of these clusters still exist to give us clues to that past era.   Westerlu...