Massive stars are made of onion-like layers, with the outer layer burning lighter elements, converting them into heavier elements that are burned in the inner layers.

Only the bigger stars can produce heavier elements.

This goes on until we reach iron. This is because these stars can pull up their temperatures higher than the smaller stars like our Sun can. There are no other appreciable sources of hydrogen in the universe. Like genealogists— experts who study the origins of people and families—these scientists can track down

during the past century, scientists have been studying how chemical elements form in stars and in outer space. After hydrogen is used up in these stars, they go through a series of nuclear burning depending on the types of elements produced, for example, neon burning, carbon burning, oxygen burning or silicon burning. Much of the iron in your body was made during supernovas of stars that occurred long ago and far away. The hydrogen in your body, present in every molecule of water, came from the Big Bang.

The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen. Elements are subdivided into several categories based on where they originated from: The Big Bang, Cosmic Rays, Large Stars, Small Stars, Supernovae, and Man-Made labs. element, were all forged inside ancient stars before being strewn across the universe when the stars exploded. People long assumed all the elements we see now were created during the Big Bang. But on May 2, 1952, an astronomer reported spotting new elements coming from …