How did our solar system get its heavy elements?
Before the planets in our solar system formed or the Sun turned on and started shining, two other stars had to die. Their deaths and later collision would seed the area where our area with many of the heavy materials needed for life on Earth. Now, 4.6 billion years later, astronomers are piecing together the story of these long-dead stars. To do this, researchers studied different ways to make the heavy elements in question – exploding stars or violent collisions between stars – along with how often those phenomena occurred, and when the elements in our solar system were first produced. Researchers Imre Bartos and Szabolcs Márka published their results May 2 in the journal Nature.
Think back to high school, and at some point you probably had to study the periodic table, a long list of all the possible configurations of materials that make up the world around us. But while we talk a lot about carbon and nitrogen, silver and gold, or even lead and uranium, the truth is that the vast bulk of the universe is made up of just two elements: hydrogen and helium.
Stars have to make all the other elements in the universe in their nuclear fusion-powered cores. And even they stop when they reach the element iron, only 26th in order on the periodic table (elements are arranged from lightest, with the smallest number of protons, to heaviest, with the most). After that, everything we have comes from more exotic or extreme processes, like the explosion of a star at the end of its life – or the dramatic collision of one star with another. The former is much more common than the latter, at least when we’re talking about neutron stars, the dense cores of massive, dead stars. They make the most dramatic collisions, only slightly less energetic than two black holes colliding. “