It's an inference from the characteristics of this cloud of ice grains that is now being seen by the cameras. (discovermagazine.com)
Weinberger designed the observations to be able to detect large water ice grains in the surface layer of the disk. (astrobio.net)
A thorough search of interstellar ice grains by infrared astronomers should determine whether radicals indeed play a primary role in constructing prebiotic molecules. (discovermagazine.com)