Scientists Successfully Replicate Cosmic Dust Formation in Laboratory Setting

A groundbreaking study by Linda Losurdo, a PhD candidate at the University of Sydney, successfully simulated extreme chemical environments in space in the laboratory. By combining nitrogen, carbon dioxide, and acetylene in high-voltage electrical plasma, she recreated a fragment of the universe inside a bottle, producing cosmic dust from scratch. The findings are published in The Astrophysical Journal; this research provides a new way to reverse-engineer the chemical history of celestial bodies. Scientists can use this process to investigate infrared spectral fingerprints to determine the chemical pathways that led to the synthesis of complex organic molecules, the building blocks of life, before the emergence of life on Earth.

Researchers experimented at the plasma physics lab at the University of Sydney. In the experiment, the team, consisting of Ms. Losurdo and her supervisor, Professor David McKenzie, used a vacuum pump to evacuate air from glass tubes, recreating the near-empty conditions of space. Nitrogen, carbon dioxide, and acetylene were then introduced. The gas mixture was exposed to around 10,000 volts of electrical potential for about an hour, creating a type of plasma known as a glow discharge. The new laboratory analysis methods allow researchers to measure the impact of ions and the temperature and pressure conditions that create dust in stellar nebulae, which may help scientists better understand the chemical composition of asteroids and meteorite materials.

Researchers have created analogues that consist of certain elements (carbon dioxide, acetylene, and nitrogen) that, when combined, make up what is known as CHON (Carbon, Hydrogen, Oxygen, Nitrogen). CHON is essential in producing organic compounds and is thought to have been brought to Earth by way of comet and asteroid impacts billions of years ago. By determining how CHON is formed under high-energy conditions, such as during a supernova, scientists will determine if the building blocks of life were formed in space before being brought to Earth. This research gives scientists an experimental framework to test these hypotheses without requiring the return of alien materials to Earth.

The ultimate intent behind this project is to build an extensive database of infrared spectral signatures developed through laboratory production of cosmic particulate matter, or cosmic dust. At present, scientists identify space-based materials via the measurement of infrared emissions; thus, the project must create a source of molecular fingerprints from materials produced under defined laboratory conditions. Once complete, this resource should help astronomers make more precise and well-supported identifications and analyses of candidate sources of interest in outer space, such as stellar nurseries and remnants of dead stars. This will further improve our knowledge of the various chemical and physical processes that have influenced the evolution of our Milky Way galaxy.