CNET también está disponible en español.

Ir a español

Don't show this again

Christmas Gift Guide
Sci-Tech

'We are made of star stuff': A quick lesson on how

Carl Sagan famously said that the death of ancient stars helped to create us. Huh? Here's a quick primer on what he meant.

607579mainhubblesupernova1200946-710.jpg
We are all descended from stars and supernovae, but what does that mean? European Space Agency and Justyn R. Maund (University of Cambridge)

Back in 1980, the late Carl Sagan blew minds with the deep thought that those very minds are made from the remnants of blown-up stars.

"The cosmos is also within us, we're made of star stuff," was the famous knowledge bomb that Sagan dropped in his original award-winning TV series "Cosmos," which recently got the reboot treatment with super space nerd Neil DeGrasse-Tyson as host.

But what the heck does that actually mean? Like everything else in astronomy, it has the effect of making me feel small and insignificant... and yes, existentially connected to everything else in the cosmos, but probably not in the way Sagan intended. "Star stuff" makes me think we are the equivalent of star dandruff, just barely clinging to the surface of the ragged old T-shirt that is our planet.

Just in time for Sagan's birthday on November 9, the American Association of Chemistry Teachers (AACT) and author Sam Kean teamed up to produce the below video to shed a little light on Sagan's iconic turn of phrase and what it really means.

Rather than the flecks of dead and discarded matter tossed off of a star that I envisioned, Kean explains that we are really the final result of a rather remarkable chain of events and chemical reactions that began in the hearts of ancient stars burning bright and eventually created all the elements that came together to form the Earth and everything that inhabits it.

Watch Kean's explanation to learn how we became much more than stellar dandruff.