Scientists from the group of Professor Brett McGuire at MIT have made a significant discovery in cosmic chemistry by identifying the presence of a previously unknown 2-methoxyethanol molecule in space. The findings of their research, published in the April issue of the magazine the Astrophysical Journal Letters, are based on observations conducted using the ALMA radio telescope in the star-forming areas NGC 6334i and IRAS 16293-2422B.
Zakhari Fried, a graduate student and the lead author of the study, highlighted the international collaboration of scientists from France, Florida, Virginia, and Copenhagen, which enabled this discovery. According to Fried, the aim is to comprehend the molecules present in the regions of space where stars and solar systems will form over time, aiding in tracking the evolution of chemistry during the process of star and planet formation.
To identify new molecules in space, researchers analyze distinctive “fingerprints” – spectra of molecular rotation, which are unique patterns of light emitted by molecules. Initially, the molecule’s spectrum is recorded in a laboratory on Earth, and then the same spectrum is sought in space using telescopes.
In 2023, the team began utilizing machine learning to identify candidate molecules for search, leading to the selection of 2-methoxyethanol. Experiments to measure its spectrum were carried out at universities in Lille, Florida, and MIT’s McGuire laboratory, spanning a broad spectrum of frequencies.
Fried stated, “We were able to observe 25 rotational lines of 2-methoxyethanol that matched the molecular signal toward NGC 6334i, enabling us to confirm the presence of this molecule in that area.” This breakthrough also facilitated the examination of the physical parameters of the molecule and potential chemical pathways of its formation from well-known interstellar precursors.
2-methoxyethanol, a 13-atom molecule, is relatively large by interstellar standards. Currently, only six kinds of larger molecules have been identified in space. The discovery of such molecules aids scientists in gaining deeper insights into the mechanisms governing molecular complexity during star formation.
Fried concluded by stating, “Observing large molecules and analyzing their prevalence enables us to progress in understanding how efficiently large molecules can be created and the specific reactions that can generate them.”