Laboratory simulation of organic grain mantles.

The most relevant conditions in interstellar space for grain mantle evolution are being simulated at Laboratory Astrophysics. In particular we have photoproduced in the laboratory a material resembling the organic refractory mantle on interstellar grains. These organic refractory samples are being analyzed by several methods, and they have been found to consist of a very complex mixture of long chains, cross-linked and probably aromatic carbon molecules.