For the first time, scientists have detected gravitational waves stemming from the crash of two ultra-dense neutron stars – and the event has spawned a new era of astronomy known as “multi-messenger astronomy.” It is believed that cataclysmic events such as these generated at least half of the gold in the Universe. Though astronomers have witnessed ripples in the fabric of space in time before (created by objects moving in the Universe), this is the first time in history the event was detectable by regular light telescopes. As a result, researchers have gained new insight into massive cosmic collisions.
A neutron star is the burnt-out core of a massive star that ran out of fuel, blew up and died. Typically 20 kilometers (12 miles) in diameter, a neutron star is radioactive and has a mass slightly more dense than the sun in our solar system. Reportedly, a handful of neutron star material weighs as much as Mount Everest! When two neutron stars combine, they spiral around each other, growing closer and closer over time. The spinning intensifies until the two objects revolve around each other several times per second. Then, a forceful impact takes place and a gargantuan gravitational wave is emitted into the Universe at the speed of light.
On August 18th, astronomers witnessed the remains of a neutron star mash-up, which traveled 130 million light years before it was seen by Earthly detectors. The phenomena resulted in dozens of scientific papers being published in top academic journals. As Phys.org reports, the observation also solved several physics riddles – including how much of the universe’s gold, platinum, mercury and other heavy elements were formed.
Said co-discoverer Benoit Mours of France’s CNRS research institute, “We witnessed history unfolding in front of our eyes: two neutron stars drawing closer, closer… turning faster and faster around each other, then colliding and scattering debris all over the place.”
Days before the highly-anticipated event, three different gravitational wave observatories based around the world picked up gravitational waves. Astronomers worked together to locate the area where the merger occurred. After narrowing it down to a very small patch in the southern sky, the US-based Laser Interferometer Gravitational-Wave Observatory (LIGO) mobilized the rest of the astronomy community, reports The Verge.
Within hours, thousands of astronomers searched the sky, eventually spotting the explosive leftovers of the neutron star mashup. Telescopes witnessed newly-forged material in the fallout. This confirmed that “maybe half, maybe more, of the heavy elements in the Universe are actually produced by this kind of collision,” said physicist Patrick Sutton, a member of LIGO. “This is a revolution in astronomy, of having thousands of astronomers focus on one source for weeks and having this collaboration unravel in seconds, in hours, then days, and weeks,” said Vicky Kalogera, an astrophysicist at Northwestern University and a LIGO collaborator. “For us, that’s the Holy Grail.”
The development comes two years after the first gravitational wave was detected (also by LIGO). For the past century, astronomers have been trying to figure out how to detect the ripples, which were predicted by Albert Einstein in his theory of general relativity.