The Universe’s Recipe Book: Astrochemistry and the Cosmic Study of Matter

The metals in your jewelry, the lithium in your phone battery, and even the calcium in your bones were created in the violent hearts of dying stars! These elements did not arise from Earth — in fact, they were born billions of years ago in distant nebulae, the recycling factories of the universe.

From stardust to smartphones, astrochemistry reveals how the cosmos craft the building blocks of everything around us — and opens room for questions about what else is left to discover.

When you hear the word chemistry, you may picture fluorescent beakers, coats and goggles, and neon liquid bubbling in high-tech labs. So how does chemistry happen in the vast and seemingly empty cosmos? Further, how do we study the chemistry of the universe from Earth?Thanks to advancements in physics and technology, scientists can decode the chemical makeup of distant stars, nebulae, and even the gases between galaxies — all without leaving our planet. The secret lies in quantum physics, the study of matter and energy at the most fundamental level.Quantum physics reveals that all atoms and molecules exhibit certain behaviour when interacting with light. Depending on the structure of these chemical species, they are able to absorb or emit light at specific wavelengths, generating unique “fingerprints” that make them identifiable!What does it mean to say atoms and molecules can absorb light? Light can act both as a wave, and as a particle, thanks to discoveries such as Einstein's photoelectric effect. Essentially, light comes in discrete ‘packages’ called photons, which carry specific quantities of energy that determine the properties of the light’s wavelength, frequency, and colour. When an atom’s electron(s) absorb a photon, they are able to jump up in energy level. However, electrons are lazy — they prefer to be at the lowest possible energy level, and will jump down the ‘latter’ of energy levels after emitting the photon back out of the atom. Since different atoms absorb and emit different energies or wavelengths, chemists can figure out their ‘fingerprints’ in the lab and provide this information as reference for astrochemists when analysing collected spectra from outer space!

Image credits: cen.acs.org

In this photo, James Webb Space Telescope meets science — the JWST’s Mid-Infrared Instrument analyzes areas around a blackhole in Stephan’s Quintet (left), a cluster of galaxies located in the constellation, Pegasus. 

This photo release marks the grand opening of JWST to science, NASA officials said. Data from these experiments will be collected in a publicly accessible archive that will spur new insights into our universe for decades to come. “The amazing thing about Webb is the speed at which we can churn out discoveries,” Rigby says. “We’re going to be doing discoveries like this every week.”

A widely used concept in the field of astrochemistry is spectroscopy. By analysing light from distant objects in space, scientists can identify which wavelengths are absorbed or emitted. This valuable information can even reveal the presence of water, ammonia, and complex organic compounds — all of which are traces of life!

Astronomers use innovative tools to discover these subtle chemical traces using various technologies. Spectrographs, coupled with large telescopes like the Hubble Space Telescope, break starlight into its component wavelengths, showing the identifiable absorption and emission lines that act as cosmic barcodes. The spectrograph, for example, uses ultraviolet light from distant quasars to map out interstellar plasma that is invisible to the human eye otherwise. For cooler molecular clouds, radio telescopes like the ALMA array in Chile detect tiny radio waves generated by molecules like carbon monoxide and methanol, allowing scientists to identify their location in nebulae — star nurseries. Furthermore, infrared observations, such asthose from JWST, can see through the dust that blocks our views in space and reveal cosmic origins of complex molecules and compounds in areas where stars, planets, and moons are formed!

For example, a current interest of astronomers includes Europa, the icy moon of Jupiter. As of 2024, NASA launched the Europa Clipper satellite , which will make multiple flybys to study the icy moon and its theorized subsurface oceans of water-ice — which were detected via spectroscopy.

By studying the chemistry of our universe, we open doors to questions that could completely change our understanding of our own origins; what are the chemical requirements for life to form? Are the building blocks of life uniform across the universe? What reactions occur in space and what can they tell us about the celestial objects we study?

Next time you look up, consider how the atoms that make up your eyes — once forged in blazing stars — now search for their origins among the space they were once created in.

Yours truly,

 Reem Soufan

Researcher, Research & Development Team