The title is meant to be attention-grabbing, but the idea behind it is simple. If alien life is ever going to be found in our Solar System outside of Earth, it will be in a world with liquid water under an icy surface. Not on Mars. This notion has not entirely escaped science fiction writers. But it deserves further consideration.
I say this for simple, straightforward reasons. Everywhere on planet Earth where water is abundant, life teems. The water can be that of a geyser in Yellowstone Park (or elsewhere), extremely hot, yet life is still found in these geysers. The glaciers of Antarctica support some life themselves, but drilling under the ice to a region where pressure is high enough to preserve liquid water has shown more abundant bacterial life below one half mile of Antarctic ice.
Jupiter's moon Europa shows clear signs of having liquid water under an icy surface. The smoothness of the planet shows cracks that appear to heal themselves as liquid water from below solidifies, as if all the features on the surface were gigantic floating glacier formations.
Saturn's moon Enceladus does even better. Not only does it have an icy surface, the Cassini probe has photographed it shooting out into space what clearly seem to be plumes of water (reminding me of the geysers of Yellowstone Park).
As early as Arthur C. Clarke's 2010 Odyssey Two in 1982, science fiction writers have been speculating that the persistent link on Earth to liquid water could mean that Europa teems with life under its relatively thin crust. But it turns out that icy moons with liquid water under the surface is a fairly common phenomenon. Among Jupiter's moons, both Ganymede and Callisto may also have liquid water deep under a thick icy crust--rather like Antarctica, though much deeper.
While a number of science fiction writers other than Clarke have noticed the potential of water oceans under icy moons, this notion has barely crept into the science fiction with a broader audience, the sci fi of films and television. If there was an episode of any of the Star Treks where an alien civilization came from underneath an icy crust, or where a crew landed to make contact with or explore the life in a sub-surface ocean, I missed it.
Our expectation in most science fiction remains that life will be found on worlds most like Earth. And not just in science fiction. NASA officials and other scientists engage in discussions of whether Mars, the most Earth-like planet in the Solar System, may have hidden water in the past; so doing obscures the actual reality of Mars being an extremely dry world with conditions that barely allow for liquid water under any circumstances. The driest place on Earth, the Atacama Desert in Chile, shows no sign of any bacteria living there at all. As a whole, Mars is drier than the Atacama.
The likelihood of life on Mars is very low and the likelihood of life in places like Europa and Enceladus is much higher. A simple notion. So why did I tag this as "Material for Christian Writers"? (of course I meant Christians who write science fiction--I do not imagine Christian writers of Romance or Suspense will be especially interested...ahem...)
It's a bit of an oversimplification, but authors who write sci fi while self-identifing as "Christian" generally tend to believe God had some role in the creation of the universe, be it as little as a guiding hand in evolution or as much as creation ex nihilo in a timeframe that matches the 6,000 year framework of Biblical genealogy. Such writers ought to be thinking about what happens when the watery oceans under these icy moons are finally explored.
If the water under these moons is as sterile as the Normal Saline Solution administered to hospital patients, that would say something about Earth being a special place, wouldn't it? Wouldn't such a finding support the idea that Earth is the unique place where God created life? Though of course materialists would not necessarily admit that's what such a finding would imply. Instead they'd search for naturalistic reasons for why planet Earth is different.
What if life under these icy moons if found, but is found to be genetically linked to life on Earth? Or even perhaps closely related to or even identical to life on Earth? Would this not point to a common Creator of life on both Earth and these other worlds? Those of us who believe in a form of divine intervention in the creation of life (no mater what kind, even if only providential) would say so. While wouldn't materialists be searching for some other reason how this could have happened? (Panspermia might get more of a boost from such a discovery instead of the concept of a common intelligent Creator.)
What if life is found, but it has no genetic relationship to any life on Earth whatsoever? Would this not imply that evolution is a strictly naturalistic process that occurs whenever the conditions are right? Of course believers in creation, especially those who believe God has providentially guided evolution, will not necessarily be phased by this. God will simply become more mysterious that we previously thought.
Still, barring the unexpected (with a sense of humility about the future--if God so wills it), it should be that whether life exists on these moons and the nature of this life will be a known fact within probably no more than fifty years. Science fiction writers of course have no power to influence what will be found during the little prediction I just made.
But we DO have the power to influence how such discoveries are interpreted and understood. By writing stories that contain such events in advance of them happening.