Molecule’s “fingerprint” may help explain formation of life on earth

The chemical element sulphur is essential for all life forms and is a building block of proteins and amino acids. By studying sulphur-based molecules in space, scientists are working to understand the chemical processes that might have led to the formation of life on Earth.

German researchers from the Max Planck Institute for Extraterrestrial Physics recently discovered a special type of molecule called singly deuterated methyl mercaptan (CH2DSH). They found it near a young star, similar to our Sun.

Using the Canadian Light Source (CLS) at the University of Saskatchewan (USask), Dr. Hayley Bunn and colleagues were able to create a “fingerprint” of the molecule by analyzing how it shakes and rotates in response to ultrabright synchrotron light. Now, other researchers on the international team are using this fingerprint or signature to look for more of the same molecules in distant space. This could enable them to piece together how the molecules for life formed on Earth, billions of years ago.

“We are really trying to understand how far we can go, chemically, toward larger biological molecules and what environments are needed to form them,” says Bunn. “Ultimately it would be nice to answer one day, how is this then inherited into planets and hopefully life?”

The CLS synchrotron was pivotal to the success of Bunn’s research, since the vibrational signals of this basic molecule are extremely hard to detect. Synchrotron light is vastly brighter than conventional sources, making it possible to identify even the faintest signals.

“There are very few – possibly four – synchrotrons in the world that do this high-resolution terahertz spectroscopy we need, and one is CLS,” says Bunn. CLS also offers researchers remote access for this type of work - with specialized support - making research as straightforward as possible.

Bunn and her collaborators were surprised at the complexity of the molecule’s signature vibrational and rotational pattern. While their study lays out clear information useful for identifying it in space, questions remain about the underlying chemistry.

Bunn is eager to continue her work identifying these fundamental molecules - in the lab and using synchrotron light, “It’s the excitement of figuring out the puzzle.”

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Bunn, Hayley A., Silvia Spezzano, Laurent H. Coudert, Jean-Claude Guillemin, Yuxin Lin, Christian P. Endres, Brant Billinghurst et al. "Laboratory Rotational Spectroscopy Leads to the First Interstellar Detection of Singly Deuterated Methyl Mercaptan (CH2DSH)." The Astrophysical Journal Letters 980, no. 1 (2025): L13.  https://doi.org/10.48550/arXiv.2501.15944

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Canadian Light Source
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