Chapter 1: Universally Speaking
Fifty one years ago men and women of the IAU (the 'I' still stood for 'International' then) gathered together in Johannesburg for a special symposium called to dicuss a range of exciting data from the probes of the Kirch mission at Jupiter:
After a year of burrowing, the Clarke cryobot had successfully melted its way through Europa's crust and had reported that the moon held a layer of (highly-saline) liquid water.
The Kirch orbiter's HASA instrument returned images from the first flyby Europa that could be interpreted as indicating, in the dry words of the mission's chief investigator, Patrick Cahill, ... extant presence of of mobile, biological organisms which exist of a macroscopic scale.'' Or: Life, big dumb animal life.
Europan Moon Cows. Lunaris Bos Bovis.
And so they gathered, biologists, geologists, psychologists, astronomers and astrophysicists come together to decide what to make of this. On the first topic, Europa's ocean, there was an easy consensus about its existence. The only real question which remained was what to name the sea. Lists of possible names were taken, precedents and policies were quoted, votes were taken, and late on the first day it was decided. In honour of it's vast unknown depths it was to be called Mare Noctis: the Sea of the Night.
In their famous debate, Klaus Mayer of Sweden's Stockholm University and Nigel Pruitt of the National University of Ireland, Galway showed just how sharply the global scientific community was divided by the controversy:
''Four percent sunlight,'' Mayer began, ''is the paramount reason against any argument that there is life on Europa on the scale that people have been deluded into believing there is! As its distance from the Europa receives only four percent of the energy from the sun that Earth receives, and this simply isn't enough energy to drive hydrolytic process that can split the ice-water into hydrogen and oxygen. The cryobots confirmed as much. The waters are anoxic. Only five percent of the Mare Noctis is composed of free oxygen, compared to the thirty six percent that you'll find in our own oceans. Tell me, Nigel, what are your so-called 'Moon Cows' supposed to breathe?''
In the fine tradition of my family, dad took a moment to ponder the question and then decided not to answer it. ''Well Klaus, with all due respect, I don't think your question is important. Kirch's shown us that the Moon Cows exist. So the big question here isn't 'is there oxygen,' but 'what can feed them?'''
Dad waved at the holograph over his shoulder. ''I spoke to John Yorn at Oxford last week, and his best guess gives the smallest Moon Cow about the same size and mass as a adult male grizzly bear. Lets say three metres long and half a metric ton? An adult grizzly needs eight thousand calories a day just to maintain its own body weight. What are the Moon Cows feeding on? Do their pods sieve Europan zooplankton? Feast on pseudo-krill? Or dine upon fine Europan salmon-analogues? Without sunlight, does Europa had a top-down ecosystem that starts with the Moon Cows? What part do the tides have to play?''
''Tides!'' Mayer interjected.