Laboratory dust experiments - Tracing the composition of cometary dust

The structure and composition of the comet nucleus are investigated theoretically on the basis of aggregation models and laboratory simulations of interstellar-grain evolution. The results are presented in graphs, diagrams, and drawings and discussed in detail. The nucleus is described as a loose tangle of rodlike grains containing about 28 percent H2O, 10 percent CO2 and CO, and 33 percent nonvolatile submicron-size grit particles (silicates, complex organics, and carbon). Evidence from meteorites suggests that the C-12/C-13 ratio of the volatile components is greater than 100.