James Webb Detects Complex Organic Molecules in Ices Beyond the Milky Way
Researchers using the James Webb Space Telescope (JWST) have identified multiple large organic molecules frozen in ice around a young protostar in the Large Magellanic Cloud (LMC), about 160,000 light-years from Earth. The observations were obtained with JWST’s Mid-Infrared Instrument (MIRI).
What was detected
The team reports spectral signatures of five complex organic molecules (COMs) within icy grains surrounding the protostar known as ST6. The detected species include:
- methanol
- ethanol
- methyl formate
- acetaldehyde
- acetic acid
According to the study, acetic acid had not been conclusively identified in space before this result. The detections of ethanol, methyl formate and acetaldehyde in ice represent the first such solid-state identifications outside the Milky Way. The data also show a spectral feature consistent with glycolaldehyde, but that identification remains tentative pending further analysis.
Scientific context
Lead investigator Marta Sewilo emphasized that JWST’s sensitivity and angular resolution made the detections possible; prior to JWST, methanol was the only complex organic conclusively detected in protostellar ices even within our own galaxy.
Implications and limitations
The team cautioned the findings do not constitute evidence of life beyond Earth. Rather, they show that organic molecules considered precursors or "building blocks" of biological chemistry can form and survive in the icy environments around forming stars and may be incorporated into emerging planets.
Next steps
Researchers plan to expand the survey to additional protostars in the Large Magellanic Cloud and to targets in the Small Magellanic Cloud to build larger samples. Currently, the LMC result is based on a single source, and there are only a few detections of complex organics in protostellar ices within the Milky Way, so a broader dataset is needed to assess variations in COM abundances between galaxies.
