  The purpose of this paper is to explore the possibility space of scenarios of
'contact'--the discovery of extra-terrestrial life, whether intelligent or
not--using a morphological approach utilising seven principal parameters,
chosen both for their descriptiveness of the scope of possibilities, as well as
for their relevance in examining potential societal impacts arising from
different scenarios, including, for example, the proximity of the discovery.
Several classes of contact scenario are examined, and existing approaches to
the search for extra-terrestrial life and intelligence are situated within the
range of possible search strategies and targets illuminated by this particular
choice of parameters, as are some examples of contact scenarios from popular
culture. The resulting possibility space can also suggest new search strategies
and potential targets, one of which is highlighted--that of 'galaxy-scale
macro-engineering'. It is hypothesised that an example of this might already be
known to us, namely the intriguing galaxy 'Hoag's Object' (PGC54559), and some
specific empirical observations are suggested in order to test this hypothesis.
Some possible extensions to the parameters used, as well as some preliminary
observations about modelling the range and extent of human societal responses
to contact, are also made.
