Molecules that could power life could originate from carbon grains

SANTA CRUZ DE TENERIFIE, March 27 (EFE).- Fullerenes, the key carbon molecules for the evolution of life in the universe, can originate from dust grains formed from highly disordered carbon and hydrogen, which the US Astrophysical Institute calls HAC. The Canary Islands (IAC) indicated this Wednesday.

The IAC explains in a statement that this conclusion was reached in a study combining laboratory chemistry and astrophysics that was published as a letter to the editor in the journal Astronomy & Astrophysics.

Fullerenes are very large, complex, highly resistant carbon molecules whose atoms are arranged in three-dimensional spherical structures that follow an alternating pattern of hexagons and pentagons, like a typical football (fullerene C60) or rugby ball (fullerene C70).

These molecules were discovered in the laboratory in 1985, which is why chemists Robert Curl, Harold Kroto, and Richard Smalley won the Nobel Prize in Chemistry in 1996.

Since then, widespread evidence of their existence has been discovered in space, particularly around the remains of old and dying stars similar in size to the Sun, called planetary nebulae, whose outer layers of gas and dust disintegrate at the end of their lives. .

Because they are “incredibly” stable molecules and difficult to destroy, it is thought that fullerenes may have served as cages for other molecules and atoms, so they could have carried complex molecules back to Earth that would have fueled the origin of life.

Thus, studying them is key to understanding the fundamental physical processes involved in the organization of organic matter in the universe, adds the IAC.

To search and identify fullerenes in space, the use of spectroscopy is crucial, a technique that allows studying the matter that makes up the universe by analyzing the chemical fingerprints left by atoms and molecules in the light that comes from them.

In a recent study, led entirely by IAC, infrared spectroscopic data, previously obtained using space telescopes, from the planetary nebula Tc 1 were analyzed.

Spectral lines indicating the presence of fullerenes are shown, but they also show broader bands, called far-infrared (UIR) bands, that have not yet been identified.

In fact, the statement continues, this unknown chemical signature has been detected in the infrared throughout the universe, from small objects in the solar system to distant galaxies.

Maro A commented. Gomez Muñoz, the IAC researcher who led the study.

In order to identify these bands, the research team reproduced the infrared emission from the planetary nebula Tc 1.

Analysis of the emission bands has made it possible to identify the presence of hydrogenated amorphous carbon (HAC) grains, i.e. highly disordered carbon-hydrogen compounds, as those responsible for the infrared emission of this nebula.

“We have combined, for the first time, the optical constants of the HAC, obtained from laboratory experiments, with photoionization models, thus reproducing the infrared emission of the planetary nebula Tc 1, which is very rich in fullerenes,” said Domingo Anibal García. Hernandez, an IAC researcher and co-author of the study.

For the scientific team, the simultaneous presence of HAC and fullerene supports the theory that the latter can form from the processing or destruction of dust grains, for example, by interacting with ultraviolet radiation, much more active than visible light.

With this result, scientists “paved” the way for future research based on cooperation between laboratory chemistry and astrophysics.

“Our work clearly demonstrates the great potential of interdisciplinarity in science and technology to achieve fundamental advances in astrophysics and astrochemistry,” concludes Gomez Muñoz.

RDG/PSS