What is the difference between a “fireball” and a “plume”?
There was some discussion among the modelers as to the most appropriate term. Now that these are observational, rather than just theoretical phenomena, it is more important to have concise definitions. Eventually everyone will converge on the same terms by consensus and common usage. In mean time, we recommend the following: Fireball : The bubble of hot gasses consisting of a mixture of Jovian atmosphere and cometary material that is shot upward by the impact. In the first moments after impact it is very hot, incandescent, and radiating in the visible and near infrared (note that the term “fire” implies heat but not combustion). Plume : The debris bubble after it has expanded and cooled adiabatically. Obviously there is not a clear distinction between the two.
