The Universe’s Gold Rush

What do cell phones, wedding rings and pharaohs’ treasures all have in common?

At first, it may not be easy to see a clear difference, considering they all relate to such vastly different topics. But in reality, all three of these items are made of heavy metals, which are the precious metals found on Earth. These include silver, gold and platinum, to name just a few. So all the atoms in the cell phone you may hold every day, or all the atoms in those precious wedding rings on people’s hands, were made from heavy metals.

But delving even deeper, where do these heavy metals come from? They definitely aren’t man-made, but how have they come to exist on Earth? This question has now been confirmed, after the collision of two neutron stars was detected in a galaxy 130 million light years away from Earth.

How It Was Detected

According to Richard D. Spencer, a reference librarian at NASA Headquarters, the detection of these two stars’ collision has been the first time anything like this has been seen.

Two degenerate stars, stars made up of non-interacting particles with pressure, in the galaxy NGC 4993 had been orbiting each other for billions of years, coming closer together as they circled one another. When they finally collided in October at a fraction of light’s speed, their impact sent 200 millions suns’ worth of energy into the universe in the form of gravitational waves, waves carrying energy through a gravitational field. 

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These gravitational waves swept across the universe, causing gravitational wave detectors in the United States’ LIGO observatory  and Europe’s Virgo observatory to sense the major event.

Spencer credits the discovery to advancements in technology, allowing scientists to observe the revolutionary event.

“This is an absolutely new discovery resulting from the breakthrough technology of LIGO (Laser Interferometer Gravitational-Wave Observatory),” Spencer said. “Initially, LIGO produced no results. But, after receiving several upgrades, the new “Advanced LIGO” went live in September 2015 and almost immediately (within minutes!) saw the waves produced by colliding black holes.”

The collision produced a pool of debris which expanded from the impact site and slowly cooled. What’s contained in this debris is the answer to our question of where heavy metals come from.

Heavy Metals on Earth

Not only does the debris contain radioactive waste products, but it also contains heavy metals such as gold and platinum. The debris forms a kind of cloud which expands, becoming the size of the solar system in about a day.

The heavy metals are initially formed by the merger releasing neutrons into surrounding space. These neutrons then mix in with other atoms, reacting to form the heavy metals. This heavy metal filled debris is shot into space. Over eons of time, the debris can come together and form new stars or settle around other planets, such as Earth.

Chemistry teacher Kavita Gupta believes this discovery is a major breakthrough in both the fields of chemistry and astronomy.

“This kind of event is really the evidence for what we’ve so long believed and that is why everybody is so excited,” Gupta said. “I hope our students can see the connection between chemistry and astronomy and space science and these are not different things. They are all interconnected. What we know in one comes from the evidence of another.”

Gupta’s explanation for how this event is evidence of a long believed theory is exactly what has attracted attention from space scientists all around the world. What has so long been  believed has finally been proved: the origins of heavy metals on Earth.

Next Steps

The spectacular merger of these two neutron stars most likely created a black hole. This was detected by NASA’s Fermi Ray Gamma Telescope which picked up gamma ray bursts, signaling the probable birth of a black hole.

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Black holes are the glamor boys of astrophysics – they’re the ones Hollywood makes movies about and the ones that almost every kid who writes to me finds so fascinating.” Spencer said. “And yet, neutron stars produce much of the heavier elements in the Universe and the discovery of gravitational waves produces (as most good science does) more questions than it answers.”

This event is sparking a new interest in space enthusiasts around the world, and people are hopeful of new technological advancements which could possibly allow us to observe similar cosmic events more often. Spencer agrees with this idea of technological advancement in the near future opening new opportunities for discoveries.

“Albert Einstein believed that science could never detect and measure gravitational waves. And yet, we now have several detectors online and more arriving soon. And eventually, the European Space Agency lead LISA (Laser Interferometer Space Antenna) will put a wave detector in space,” Spencer said. “This is an absolutely revolutionary field of astronomy and the scientists in the field are ecstatic.”