I have been moved. Lee Billings at Aeon writes about the decent chance for life on Europa, relative to Mars at least, and makes a strong case for making it a much bigger exploratory focus than our dead, red neighbor. But even more fascinating is his speculation about how the discovery of life on Europa could indicate the possibility for life on any other enclosed and water-rich world:
[I]f water and life could exist [on Europa], why not in the hearts of large comets, before the Sun’s planets and moons even finished forming? Our solar system might have brimmed with hidden life for nearly as long as the Sun has shined, and ice-roofed worlds might be the default abodes for biology in the Universe. Life within a roofed world could proceed swimmingly against any number of otherwise-fatal cosmic calamities, whether being slingshotted into the interstellar dark as a rogue planet, or being bathed in hard radiation from a nearby supernova or burping black hole. We could then guess why, like our solar system, the Universe at large looks so desolate to us. In this scenario, most life, even if it had eyes to see, would never glimpse sky, stars, light, or fire, and would have scant hope of ever reaching what lies above and beyond its icy shell.
Carl Sagan famously said that we sentient Earth-beings are “a way for the Universe to know itself,” and it’s a stirring thought. But’s at the same time stirring and even troubling to imagine the possibility of entire ecospheres, perhaps with intelligent species, encased on ice worlds and more or less totally unaware of what lies beyond their frozen ceilings. These beings are of course entirely hypothetical, completely made up, but as I think about even the possibility of eternally-roofed-in beings, I feel a sense of claustrophobia for their lot, and sadness that they might never get the glimpse of the wider Universe to which we land-dwellers have been privileged.
It’s silly, I know. And of course, if we’re just making things up, we can imagine that they evolve to the point of transcending their environment, and that somewhere in the Cosmos, on some comet, moon, or frozen planet, a brilliant, brave, and technologically-augmented creature is breaking through the ice, and for the first time in its species’ history, drinking in the stars.
Assuming they have eyes, of course. Which they probably don’t because there’d probably be no light source in their normal habitat to necessitate an eye’s evolution.
But you never know.