New UA study shows how complex molecules form in space, has implications for origin of life

By Jill Ryan
Published: Friday, July 8, 2022 - 4:52am
Updated: Friday, July 8, 2022 - 8:30am

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An illustration of a "Buckyball," or a C60 molecule
Jacob Bernal/University of Arizona
An illustration of a "Buckyball," or a C60 molecule

What is the meaning of life? Well, that can be up to interpretation. Now, what’s behind the formation of life? Well, that’s carbon. 

new study out of the University of Arizona shows a connection between dying stars and the creation of complex carbon molecules. Not quite as complex as a life-form, but this study has implications for the origin of life.

A picture of Jacob Bernal, lead author of the study
Jacob Bernal/University of Arizona
Jacob Bernal, Ph.D., UA postdoctoral fellow and lead author of the study

The universe is a hostile place. And that means carbon has a tough time sticking around. Which makes the existence of humans and other carbon-based earthly life-forms even more confounding.

Jacob Bernal is a National Science Foundation postdoctoral fellow at UA. He says these “regular organic molecules, have difficulty surviving intense cosmic rays” and other obstacles in space. He says our molecules are complicated, because DNA is made up of billions of atoms.

“We don't know how cells form and we are humbled by the simple cell, and there's a lot more exploration that's needed for the chemistry of the origins of life," Bernal said.

So scientists are starting small. The largest complex carbon molecule known to exist in the space between stars, aka the interstellar medium, was discovered in the mid-1980s. Nicknamed Buckyballs, these molecules are made up of just 60 carbon atoms. And C60, as it’s otherwise called, is resilient in space. 

But a question remains: how did these complex molecules form in such a hostile environment?

That’s what Bernal’s new study is about. He worked with two UA collaborators. Chemistry and astronomy professor Lucy Ziurys, Ph.D., is one of them. 

A picture of Lucy Ziurys, one of the collaborators of the UA study
Jacob Bernal/University of Arizona
Lucy Ziurys, Ph.D., UA professor and one of the collaborators of the UA study

“There are little dust grains out in space; they're actually formed in dying stars. And a lot of these dust grains are composed of something called Silicon Carbide. And we've shown that when you heat up these little Silicon Carbide grains rapidly that C60 naturally forms,” Zuirys said.

Bernal says their experiments also produced an even more complex molecule — called carbon nanotubes. These nanotubes are 15 times larger than Buckyballs.

“This has implications for dust grain studies, for solar system formation. Again, this would represent a very large jump in our knowledge of how complex chemicals can be out in space," Bernal said.

Carbon is forming where carbon shouldn’t exist and therefore, Zuirys says, it has implications for the origin of life in the universe.

The next step is more discovery. Carbon nanotubes tubes have not been directly observed in space, but this study suggests they’re out there just waiting to be found. 

Further analysis may come as soon as next year, as NASA's UA-led OSIRIS-REx space mission comes back with asteroid samples. 

A picture of Tom Zega, one of the collaborators of the UA study
Jacob Bernal/University of Arizona
Tom Zega, Ph.D., UA professor and one of the collaborators of the UA study

Tom Zega, Ph.D., is a professor in the university’s Lunar and Planetary Lab. He is the study’s third collaborator. 

“We may very well find in those samples, the kinds of things that this project has been investigating," Zega said.

Zega says Asteroid Bennu is made up of materials from different places, and maybe one of those places was near a dying star. 

“And among those places could be these circumstellar, these interstellar environments and could preserve small grains of C60 and nanotubes," Zega said.

 Samples are expected back in September 2023. Leaving discovery for another day. 

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