MYSTERY METAL

Astronomers remain puzzled about source of gold

Astronomers have a pretty good understanding of where the matter in our universe comes from. In the beginning, there was only hydrogen, helium and a tiny smattering of lithium. Everything else, the oxygen we breathe, the carbon that makes up so much of our bodies, the silicon, magnesium, aluminum and other elements that make up our planet, were all formed inside stars and released into the wider universe when stars explode.

But there is one element that still has astronomers bumfuzzled: gold. There is too much of it. Supernova explosions can't begin to account for the amount that we see because the gold is trapped in the neutron stars, the remnants of supernovas.

Colliding neutron stars release prodigious amounts of gold, as do so-called magneto-rotational supernova. These rare supernovas spin so fast and generate such strong magnetic fields that they literally turn themselves inside out. This releases all of their trapped gold atoms. But while both produce extraordinary quantities of gold, they are extremely rare and cannot begin to account for all the gold we find here on Earth.

Chiaki Kobayashi is an astrophysicist at the University of Hertfordshire in the United Kingdom. She led the new study to determine the origin of gold. “There's two stages to this question,” she said. “Number One: neutron star mergers are not enough. Number Two: Even with the second source, magneto-rotational supernova, we still can't explain the observed amount of gold.” Kobayashi and the other study authors accounted for the formation and relative abundance of all elements from carbon to uranium. All except for gold. Its abundance remains a mystery.

So, the next time you put on that gold ring or necklace, you can marvel that our Earth has as much gold as it does.

Planet Visibility Report

• Go outside about 5:30 p.m. Nov. 18. Find Jupiter and Saturn in the southwest. They'll be easy because the thin crescent moon sits just below them. Go out again at the same time on Nov. 19 and you'll see the moon is now just above the two planets. Overnight, when all three celestial bodies were below our horizon, the moon slowly crept past the two planets. We only get to see the beginning and ending points of this pair of celestial conjunctions.

• As the month begins, Mercury and Venus shine in the morning twilight while Mars, Jupiter and Mars brighten the evening sky. By mid-month, Mercury begins diving toward the sun to disappear into the evening twilight by the last week of November. Meanwhile, all three evening planets move inexorably toward the sun but remain visible all month. New moon occurs on Nov. 15, with the full moon — and a rather minor lunar eclipse — following on Nov. 30.