On August 17, 2017, about 70 telescopes collectively turned their gaze to a fiery collision between two dead stars that took place millions of light-years away. The telescopes watched the event unfold in a rainbow of wavelengths, from radio waves to visible light to the highest-energy gamma rays. As the pair of ultra-dense neutron stars crashed into each other, they flung debris outward that glowed for days, weeks, and months. Some of the onlooking telescopes spotted gold, platinum, and uranium in the searing blast, confirming that most heavy elements in our universe are forged in this type of cosmic collision.