In dark, cold clouds where stars are just beginning to form, dust grains put on icy coats. This ice is not just frozen water: it contains dissolved carbon dioxide, methanol, ammonia, and other molecules. Astronomers pointed the James Webb Space Telescope at four such baby stars and spread their light into spectra, like a rainbow, to learn the composition of the ice. It turned out that the icy shells hide not only simple molecules but also more complex ones — for example, ethyl alcohol and substances resembling the building blocks of amino acids.
The scientists compared the obtained spectra with results from laboratory experiments where similar ices were created in vacuum chambers at very low temperatures. They found that complex molecules can assemble from simple ones right in the ice when radiation hits it. But not all lines in the spectra could be precisely attributed to specific substances — some bands overlap, and additional data are needed. It's like trying to pick out a single singer in a choir of many voices: sometimes their voice blends with others.
Such studies help us understand where organic molecules in space come from. Perhaps the icy shells of dust grains were the first chemical laboratory where substances were prepared that later ended up on young planets.
In the icy shells around young stars, ethyl alcohol was found, the same substance that is in alcoholic drinks.
In Carl Sagan's novel "Contact," a signal from space contains complex information, and here the chemistry of ice itself may carry a message about future life.