Rare Elements

StarDate: August 13, 2013

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Most of the elements on Earth — from the oxygen we breathe to the iron flowing through our veins — was created in stars that died before our planet was born. But there are a few prominent exceptions to this rule. In fact, stars actually destroy three elements, which means we must look elsewhere to find their origin.

Lithium, beryllium, and boron are lightweight — only hydrogen and helium are lighter. And because stars destroy these elements, they’re rare. There’s a hundred thousand times more carbon — which stars make in abundance — than all the lithium, beryllium, and boron in the universe put together.

Astronomers think these rare elements are created in large part not in stars but far from them — in the vast spaces between stars. These spaces contain lots of the slightly heavier elements carbon, nitrogen, and oxygen. Occasionally, one of these atoms gets zapped by a high-speed charged particle known as a cosmic ray, splitting the atom’s nucleus. It’s like the first shot in a game of pool, when the cue ball hits the 15 other balls on the pool table and scatters them.

Over time, some of the newly minted lithium, beryllium, and boron drift into clouds of gas and dust that give birth to new stars and planets. Nuclear reactions soon destroy the atoms that are unfortunate enough to become part of a star. But the atoms that become part of a planet survive — explaining their presence here on Earth.

 

Script by Ken Croswell, Copyright 2013

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