Unraveling the Mystery of Methanol Formation in Space: A Paradigm Shift
Imagine a star's birth, surrounded by a swirling cosmic cloud, where planets, moons, and asteroids take shape. But how do these celestial bodies form? This captivating question drove astrochemist Julia Santos during her PhD journey.
"I aim to unravel the chemistry of space," Santos shares. "When we envision a planet, we picture a core, a mantle, a surface, and an atmosphere. Achieving this requires the perfect blend of atoms. I'm curious about the distribution of these ingredients across the universe. Are they unique to Earth, or do they exist around other stars as well?"
Unveiling the Chemistry of Planetary Nurseries
When a star ignites, it's enveloped by a massive cloud of gas and dust, the raw material for planets, moons, and asteroids. However, the precise chemical journey from dust to planet remains elusive. Santos illuminated the initial steps of this process.
"How do molecules evolve into more complex forms? How are they created and destroyed? Are they in a gaseous or solid state? These are the mysteries I seek to unravel," Santos enthuses. "During my PhD, I focused on dust grains and the ices that form on them, creating a thriving environment for chemical reactions."
Simulating Space in a Terrestrial Laboratory
Santos primarily conducted lab experiments to explore these questions. "In our solar system, we might send a probe to a comet. But for distant celestial bodies, that's simply out of reach," she explains. "So, we recreate interstellar space on Earth in an experimental setup with extremely low temperatures and pressures."
Santos pursued various avenues, from laboratory experiments to chemical studies and observational programs. "Hands-on experiments are particularly rewarding," she adds with a smile.
Debunking a Long-Standing Paradigm
Santos's research achievements began during her Master's, where she authored several refereed papers, two as the first author. But her most significant accomplishment came during her PhD. "I studied numerous chemical reactions, with a focus on methanol formation. It's a simple molecule in space, yet considered complex," she clarifies. "Methanol is the cornerstone of astrochemistry, the fundamental building block for many organic molecules."
The prevailing paradigm for methanol formation, established 20 years ago, was challenged by Santos's work. "I confirmed that there's another mechanism that's more significant," she reveals. "We published our findings in 2022, and since then, observations and models have supported our theory. In astronomy, empirical evidence is rare, so this was an exciting development!"
A Hub for Astrochemistry in Leiden
According to Santos, the lab and community in Leiden are exceptional. "We're fortunate to have facilities and expertise that are hard to find elsewhere. Astrochemistry is highly multidisciplinary, encompassing geology, engineering, astronomy, and chemistry. Leiden offers all of this, which was incredibly helpful and enriching."
Santos also faced challenges. "My promotor, Harold Linnartz, passed away unexpectedly. It was a difficult time," she recalls. "And soon after, we had to move the lab to the Gorlaeus Building, which meant I couldn't conduct experiments for a significant part of my PhD. Fortunately, Ewine van Dishoeck welcomed me into her group."
Santos continues her research at Harvard University with the prestigious 51 Pegasi b Fellowship.
