Fiona Wolf / The University of Sydney
Linda Losurdo (left) with her advisor, Professor David McKenzie, in the plasma physics laboratory at the University of Sydney
A new study from the University of Sydney in Australia has reconstructed the chemical composition of key molecules in stars by analyzing their infrared fingerprints.
A doctoral student has recreated a small portion of the Universe inside a laboratory, producing synthetic cosmic dust and offering new insights into how the chemical ingredients for life may have formed long before Earth existed.
Linda Losurdoa PhD student in materials and plasma physics at the School of Physics at the University of Sydney, carried out the experiment with a simple mixture of gases — nitrogen, carbon dioxide and acetylene.
The assembly was designed to replicate extreme conditions and highly dynamic elements found around stars and within supernova remnants.
When exposed to strong electrical energythe gas mixture produced carbon-rich particles that resemble cosmic dust found adrift in interstellar space and inside comets, asteroids and meteorites.
The results were recently published in the journal The Astrophysical Journalfrom the American Astronomical Society.
The material created in the laboratory contains a complex combination of carbon, hydrogen, oxygen and nitrogen, commonly called CHON molecules. These elements form the basis of many organic compounds essential for life.
“We no longer need to wait for an asteroid or comet to reach Earth to understand its history”, explains Losurdo, cited by . “It is possible to build analogous laboratory environments and reverse engineer its structure using infrared fingerprints.
“This could give us enormous insight into how ‘cosmic carbonaceous dust’ can form in the plasma expelled by giant, old stars, or in cosmic nurseries where stars are being borndistributing these fascinating molecules that can be vital to life“, he adds.
“It’s as if we had recreated a little bit of the Universe in a bottlein our laboratory”, concludes the researcher.
A cosmic dust it forms in highly energetic regions of space, where molecules are continually bombarded by charged particles such as ions and electrons.
Scientists detect this material measuring its infrared emissionwhich works like a molecular fingerprint, revealing its composition.
Dust produced in the laboratory presented the same patterns distinctive infrared, demonstrating that the experience faithfully reproduces the processes occurring in space.
Extraterrestrial material may have seeded life
One of the great questions in science is how life began on Earth.
Researchers continue to explore whether the first organic molecules formed on the planet itself, arrived later via comets and meteorites, or were delivered during the early stages of the solar system’s formation — or some combination of these possibilities.
Between about 3.5 and 4.56 billion years ago, Earth suffered an intense bombardment of meteorites, micrometeorites and interplanetary dust originating from asteroids and comets.
These impacts will providegone large amounts of organic material to the planet’s surface, although the origin of this material remains uncertain.
“The covalently bonded carbon and hydrogen in the material of comets and asteroids are believed to have become formed in the outer shells of starsin high-energy events such as supernovae and in interstellar environments”, says Losurdo.
In his experience, Losurdo and his advisor, professor David McKenzieused a vacuum pump to remove air from glass tubes, recreating the conditions of almost empty of space.
Next, nitrogen, carbon dioxide and acetylene were introduced into the system. The gas mixture was exposed to a electrical potential of around 10,000 volts for about an hour, forming a plasma known as a glow discharge.
Under these high-energy conditions, the molecules fragmented and eventually broke apart. recombine into more complex structures. which settled as a thin layer of dust on silicon wafers placed inside the tubes.
The resulting material sometimes has the appearance of shimmering, glitter-like particles.
Cosmic dust gas mixture: Linda Losurdo mixed basic gases in a tube and subjected them to electrical bombardment to create cosmic dust analogues
David McKenzie, co-author of the paper, explains that this approach allows scientists investigate environments that cannot be directly observed in space.
“By producing cosmic dust in the laboratory, we can explore the intensity of ionic impacts and the temperatures involved when dust forms in space,” says the professor.
“This is important for understanding the environments inside cosmic dust clouds, where it is thought that life-relevant chemistry is occurring“, he adds.
“This also helps us interpret what a meteorite passed through or an asteroid fragment throughout its existence. Your chemical signature keeps a record of your journey, and experiences like this help us learn to read that record”, concludes the researcher.
