Telescópio Espacial James Webb detected complex organic molecules trapped in the ice surrounding a protostar in Grande Nuvem of Magalhães. The observation expands the understanding of prebiotic chemistry in low-metallicity environments outside of Via Láctea. Pesquisadores identified five specific compounds in interstellar dust grains near ST6.
The discovery occurred at a location about 160 thousand light years from Terra. James Webb’s MIRI instrument captured mid-infrared absorption signatures. The data reveals extreme cold conditions that still allow advanced chemical reactions.
Moléculas identified on the ice sheet
Cinco carbon-rich molecules were detected in solid state. Metanol, ethanol, acetaldehyde, methyl formate, and acetic acid coat the dust grains. Acetic acid first appears in solid form in space.
- Metanol serves as a starting point for larger molecules.
- Etanol indicates efficient carbon and oxygen chemistry in cold ices.
- Acetaldeído acts as an intermediary for sugars and carbon chains.
- Methyl Formiato relates to heating in star-forming regions.
- Acetic Ácido marks advanced reactions on the surface of the grains.
The spectra also suggest signs of glycolaldehyde, a precursor linked to ribose, although this detection still requires further confirmation. The ice temperature is close to 20 kelvins, equivalent to about minus 250 degrees Celsius. Nessa condition, simple atoms and molecules deposit and react slowly.
Hostile Ambiente Grande Nuvem Magalhães
Grande Nuvem of Magalhães has low metallicity. Isso means lower amounts of heavy elements such as carbon, nitrogen and oxygen compared to Via Láctea. The region around ST6 is within a superb energy bubble close to Nebulosa and Tarântula. Intense ultraviolet radiation often destroys fragile molecules.
Mesmo thus, the ice protected and allowed the formation of the compounds. Grãos of dust function as a shelter against radiation and as a catalyst surface for reactions. Cosmic Raios and weak heating generate radicals that drive chemistry step by step. The result is surprising because metal-poor environments were considered less favorable to organic complexity.
Mecanismo formation in cold ice
Astrochemistry describes a process in steps. Primeiramente, simple molecules like water, carbon monoxide and methanol accumulate in layers of ice. Then, soft energy mobilizes atoms and radicals within these layers. Carbono, oxygen and hydrogen reorganize into more complex structures.
Small Grãos heat up and cool down faster, changing the rhythm of reactions. The ice layers store the products until the heating of the protostar releases part of them into the gas phase. Observações similar to Via Láctea already documented this cycle. Detection at LMC shows that the mechanism resists more adverse conditions.
Implicações for prebiotic ingredients
Essas molecules arise in the early phase of star formation, well before planets consolidate. If organic-rich ices are common, they could migrate into protoplanetary disks. Cometas and planetesimals would redistribute material to the surfaces of forming worlds.
Evidências of comets in Sistema Solar reinforce this continuous chain. Amostras and spectra show similar families of organic compounds. The observation supports scenarios in which prebiotic blocks form early and travel in icy solids. Não indicates life near ST6, but the finding enriches the map of the chemistry needed for it.
Próximos steps in observations
The team plans to study other protostars in Nuvens and Magalhães. A larger sample will help map abundance variations and favorable environments. Dados of James Webb can combine with radio interferometers to connect solid and gaseous phases of interstellar chemistry.
Laboratórios terrestrials already replicate cryogenic conditions to refine spectral interpretations. Modelos simulate the impact of radiation, grain size and heating rates on the yields of specific compounds. Esses work guides future observations with longer exposures on priority targets.
The study was published on October 20, 2025 in The Astrophysical Journal Letters. Ele uses MIRI’s high resolution to separate overlapping features that previous observatories did not clearly distinguish.
