How do we know we are “Made of Star Stuff”?
This is a gorgeous image of a stellar jet in the Carina Nebula. The Carina Nebula is mostly made from hydrogen along with other elements such as oxygen and sulphur. Life on earth is made up of some of these very same elements. We are star stuff. But how do astronomers know without physically testing the gas and dust clouds?
Through astronomical spectrospocy, signatures of all the elements in the gas and dust in the Universe can be identified. Each atomic element has a distinct pattern of “spectral lines” when observed through light. A spectral line is an actual dark or bright line that is revealed out of an otherwise continuous spectrum of light. They result from a deficiency or excess of photons compared with the nearby frequency. No element has the same pattern so in a way they are like atomic fingerprints. These patterns of lines can be observed here on Earth enabling astronomers to compare the patterns to objects observed in outer space. If there is a match between specific patterns, then the elements being observed can be identified.
Tonight on Cosmos, spectral lines are highlighted demonstrating how the entire cosmos, the planets, the stars, nebulae, galaxies and all of life is all made of the same stuff.
(Image Credit: NASA, ESA, and the Hubble SM4 ERO Team)