Inoculating Enceladus

The discovery of environments in the Solar System that possess conditions capable of supporting known types of life raises the question of whether they could be deliberately inoculated in order to study the process of the emergence of biospheres. We discuss the case of Enceladus, the first planetary body to convincingly be shown to possess all the requirements for habitability in the present-day, and consider ways in which inoculation would be achieved. We present examples of the scientific questions that might be investigated. The compelling science that could be done shows how habitable worlds will create new ethical questions. As we might not have certainty on their status as being uninhabited, we would have to decide on a principled objection to any inoculation experiments or whether some level of confidence in their status as being uninhabited, determined by a suitable sampling regimen, would allow for inoculation. As the inoculation of extraterrestrial oceans, causing planetary scale changes, might be accomplished in a far shorter time scale than, for example, the more speculative terraforming of a planet such as Mars, the scientific possibilities and their attendant ethical challenges potentially represent a near-term challenge.