In the coldest, darkest corners of space, dust grains get covered in ice, like a window on a frosty day. This ice isn't just frozen water: it also contains carbon monoxide and carbon dioxide. From such ice, comets and planets may eventually assemble. But until now, it was unclear how the dust grain itself affects the ice that forms on it.
Scientists took two kinds of surfaces: a smooth plate and porous dust similar to cosmic dust. They sprayed those gases onto them at minus 263 degrees Celsius — colder than on Pluto. Then they watched how the ice absorbed light and at what temperature it evaporated.
This means that in real cosmic clouds, which are full of dust, ice may behave very differently than in simple models. For example, it might hold onto gases longer, gases that later become building blocks for planets. Now, when astronomers look through telescopes at distant clouds, they can better understand what's happening there.
In space, ice can evaporate not only from heat but also from the ultraviolet light of stars, which breaks ice molecules apart.