It was a faint signal, but it told of one of the most violent acts in the universe, and it would soon reveal secrets of the cosmos, including how gold was created, per the AP. What astronomers witnessed in August and revealed Monday was the long-ago collision of two neutron stars—a phenomenon California Institute of Technology's David Reitze called "the most spectacular fireworks in the universe." Measurements of the light and other energy emanating from the crash have helped scientists explain how planet-killing gamma ray bursts are born, how fast the universe is expanding, and where heavy elements like platinum and gold come from. In short, the collision is ushering in "a new era in astronomy," per the Washington Post. The crash, called a kilonova, generated a burst of gamma rays and a gravitational wave, a faint ripple in the fabric of space and time theorized by Einstein.
The signal arrived on Earth on Aug. 17 after traveling 130 million light-years. NASA's Fermi telescope, which detects gamma rays, sent out the first alarm. Then, 1.7 seconds later, gravity wave detectors in Louisiana and Washington state that are a part of the LIGO Laboratory, whose founders won a Nobel Prize earlier this month, detected the crash. The colliding stars spewed bright blue, super-hot debris that was dense and unstable. Some of it coalesced into heavy elements, like gold, platinum, and uranium. Scientists had suspected neutron star collisions had enough power to create heavier elements, but they weren't certain until they witnessed it. "We see the gold being formed," said Syracuse University physics professor Duncan Brown, one of more than 4,000 scientists involved in the resulting blitz of science. "This is our fantasy observation."