Globular cluster M15 in our galaxy is an ancient stellar soup. Why do its stars differ in composition? By spreading starlight into a rainbow (spectroscopy), the Keck telescope revealed: in the first generation, heavy element abundances vary, while in the second they’re uniform. Like a poorly stirred soup: at first, you scoop up chunks or broth, but later it evens out. This means the gas for early stars was clumpy, and only later mixed.

This difference suggests the source of heavy elements ignited early and then quickly fizzled out — otherwise the unevenness would have persisted into the second generation. This fits the signature of neutron star mergers. And here’s a twist: the gold in your ring might have been forged in just such a burst, which “salted” M15’s gas over 10 billion years ago.