Comets are widely assumed to be debris from the formation of our Solar System and therefore attract considerable interest from scientists and space agencies. Spacecraft observations in the vicinity of an active comet always have limitations. To maximize our understanding, we need to produce a chain of models that allows us to compare, in a self-consistent way, the data from several different instruments. Only in this way can we use all the constraints on the large number of free parameters. The Planetary Imaging Group at the University of Bern has produced such a chain of models. This is showing us that, for example, dust and gas emission from the nightside of the nucleus (where there is no direct solar energy input that is supposed to drive the flow) is surprisingly strongly.
The presentation will discuss why researchers are particularly interested in comets, some of the modelling tools we use, and what we are learning from them.