Hermann Boehnhardt, Fred Goesmann (MPI for Solar System Research, Katlenburg-Lindau), 
GianPaolo Tozzi (INAF Arcetri Observatory, Florence), Stefano Bagnulo (ESO Santiago de 
Chile), Ludmilla Kolokolova (Univ. Maryland, College Park)

Comets may have played a role in the creation and evolution of life on Earth through 
catastrophic impacts that have caused local and global extinction of life forms, through the 
provision of water to the surface thus contributing to the formation of oceans on Earth, and 
through the potential delivery of biologically relevant material for the creation of life. 
The latter is the most interesting, however also most uncertain scenario. There are 
observational indications for the presence of organic compounds in comets, both in the form 
of frozen ices and in the dust phase (CHON material), that allow to speculate about the 
relevance of comets for life on Earth. However, more direct measurements address the 
chirality of cometary material through remote sensing and in-situ experiments: circular 
polarization of cometary dust in comet 73P/Schwassmann-Wachmann 3 and chirality of nucleus 
material at the surface of comet 67P/Churyumov-Gerasimenko. The former was measured in 
June/July 2006 using FORS1 at the ESO VLT; the latter will be measured by the COSAC 
instrument on-board the PHILAE lander of ESA’s ROSETTA mission. The presentation explains 
the current knowledge and available results and addresses the expectations for the 
forthcoming decade.