Page 31 - The 'X' Chronicles Newspaper March/April 2018 Edition

Alien Origins of Europium 31

Scientists are solving the

alien origins of Europium,

a strange metal found in

TVs, plastics, and lasers

by Dave Mosher

In October 2017, astrophysicists announced a
remarkable discovery: The first-ever detection
of two dead stars smashing together.
The collision created gravitational
waves, or ripples in spacetime, which were
"heard" by the LIGO experiment. But the event
— unlike merging black holes— threw off gobs
of neutrons (essentially super-heavy-element
barf).
This material almost immediately
decayed into lighter elements, leading to a
bright, radioactive "kilonova" astronomers
incredible speeds. Those neutrons are very hot (LIGO) experiment finally detected these
could see some 85 million to 160 million light-
and crowded, so they smash together while cosmic reverberations on Sept. 14, 2015, thanks
years away from Earth. Light from the energetic
moving outward, forming giant atomic cores. to the fearsome collision of two black holes
breakdown of this material suggest that it led to
Because very big atoms are highly about 1.3 billion light-years from Earth. They
the unimaginably valuable formation of about
50 Earth masses' worth of silver, 100 Earth unstable, they almost immediately break apart announced the discovery on Feb. 11, 2016, after
masses of gold, and 500 Earth masses of and decay into smaller atoms — stuff like months of exhaustive verification.
platinum. platinum, gold, silver, and europium. Then, in June 2016, the 900-scientist
Researchers who've pored over the data Fortunately, we don't need a spaceship LIGO team announced their second detection,
since last year now think the collision also made to find this stuff created by neutron stars — it's made on Dec. 2016, 2015.
here on Earth. Countless smash-ups over the "It confirms — it super-confirms — that
1-5 Earth masses of a very rare element called
millennia spread around enough of these exotic these events are not flukes," astrophysicist
europium, according to a recent study in The
metals that when our planet formed, they were Vicky Kalogera, who has been working with
Astrophysical Journal. (They also dialed back
baked right into its crust. LIGO to analyze the signals, previously told
the gold-formation estimate to 3-13 Earth
masses worth.) "The rate of these neutron star mergers Business Insider. "They're happening in nature
The study could mean that neutron-star in our galaxy is about one every 100,000 years. and we can detect them every few months."
collisions are responsible for forging most of On human time scales, that's a long time," After an upgraded "Advanced" LIGO
the europium and gold we find on Earth, not to Duncan Brown, an astronomer at Syracuse boots up this fall, Kalogera and others think the
mention other key elements. University who's a member of the LIGO experiment could detect 10 or more new
research collaboration, previously told Business gravitational waves over the next year — and
Insider. "But on galactic time scales, when possibly up to 100 a year later on, with the help
What europium is and how it's made
you're creating stars and solar systems, that's not of another experiment called Advanced Virgo.
that much time." Business Insider previously spoke with
Europium is element number 63 on the Periodic
What's still uncertain is how much Imre Bartos, also a physicist working with
Table, and it's a somewhat hard, silvery metal
that reacts with oxygen and water — so it's colliding neutron stars might contribute to LIGO, and other researchers earlier this year
europium. If LIGO finds more and more about the "revolutionary" new era of astronomy
never found in pure form. When it is pure, it's
colliding neutron stars over the years, it's likely they say has begun.
stored in inert gases (e.g. argon) to prevent it
those events — not supernovas — are where the Here are just a handful of formerly
from oxidizing and tarnishing.
most valuable materials on the planet come impossible things astronomers could do with
The element is used to make some red
from. [] gravitational waves. []
lasers, electronic parts, and the red phosphors of
cathode-ray-style television sets. (One estimate
suggests there's 0.5-1 gram of europium in A year ago, scientists
every CRT screen.) Its ability to react to cracked one of Einstein's
ultraviolet light also makes it an anti-counterfeit
measure in euro paper currency. greatest mysteries — now
Europium is also seeing newfound use
in ultra-bright-red LEDs and — if the a bizarre new form of
technology pans out — could lead to a stable astronomy is emerging
quantum hard drive.
Researchers suspected europium was
formed by colliding neutron stars, but couldn't A year ago Tuesday, scientists inside two giant
be sure how much until one was detected. L-shaped instruments saw a strange blip on their
Another explanation is that cataclysmic screens they could hardly believe.
explosions of stars, called supernovas, form It was the first evidence of gravitational
most europium and other elements heavier than waves— ripples in the fabric of space that
nitrogen. careen across the universe, right through
A bit of nuclear alchemy called the everything and everyone.
rapid process or r-process is what drives the Einstein first predicted their existence
creation of such heavy elements. 100 years ago, yet the famous scientist doubted
The r-process goes something like this: we'd ever find any.
As neutron stars move toward each other, a tiny However, scientists from the Laser
bit of their material gets shot into space at Interferometer Gravitational-Wave Observatory