In our grand quest for the meaning of life, let me take you on a journey that starts in the outer reaches of the solar system. Ever since the Cassini spacecraft made it to Saturn a few years ago, we've been getting to know the sixth planet out from the sun, the beautiful ringed planet with all the moons. It turns out one moon in particular holds a special surprise that we're just beginning to unwrap. Enceladus has a liquid ocean a few kilometers under its icy crust, resting on a solid rocky core. How amazing is that - an ocean out so many millions of kilometers further from the sun, where the sun is a bright star and surface temperatures are near absolute zero at high noon. A salty ocean of water, imagine that! I wonder if we could go swimming?

 

It turns out there are nanoparticles of silica already making their way through that ocean, and I want to tell you the story of one nanoparticle's journey.

 

It starts as part of a rock, the rocky core of the moon. It's a tiny speck of matter, almost but not quite inconsequential. Hydrothermal jets shoot through the rocky core, pulling this speck out of its nest. After forming at the cooling edges of hot, silica-rich fluids gushing into the cold surrounding ocean, our nanoparticle will spend as much as a few years drifting up through 60 kilometers of open water.

 

When it reaches the top of the ocean, the nanoparticle ascends into water-filled fractures that crisscross through the few-kilometer-thick overlying frozen crust of the south polar terrain. Because the seawater is denser than the surrounding ice, its progress upward should halt less than a kilometer underneath Enceladus' surface. But here the champagne effect provides a boost - as the water, which contains dissolved carbon dioxide, rises, and the pressure on it decreases, it become fizzy. The bubbles help to lift the seawater within perhaps 100 meters of Enceladus' surface.

 

There, we suspect, it pools in ice caves. In such close proximity to the harsh vacuum of space, bursting carbon dioxide bubbles and low pressures make the pools effervesce, throwing off clouds of mist and water vapor. The droplets of mist quickly freeze into micron-sized ice grains, which encase our silica nanoparticle like a raisin in a bun. The vapor rises up through channels in the brittle and dry near-surface ice, as if through a chimney. Some of the vapor freezes on the walls of the ice, but our nanoparticle is carried within its vapor up to the surface, hurled into space in icy fountains.

 

Most of the ice grains in the plum fall back to the surface as snow, but some, including ours, escape the gravity of the moon and accumulate in one of Saturn's rings. The E ring is built entirely out of ice grains from Enceladus' ocean. In the E ring, ionized gas erodes the ice grains and frees our embedded nanoparticle. The liberated nanoparticle accumulates an electric charge and plays in Saturn's immense electromagnetic fields. Until... one day a solar wind comes through, and boosts our nanoparticle to velocities up to a million kilometers an hour. Off it zips to the outer solar system at 1 percent the speed of light. It may even reach interstellar space, to surf the voids between the stars.

 

The last four paragraphs were adapted from an article in Scientific American, October 2016. As I read it, I was enchanted to imagine a modern version of a Soul's Progress.

 

We first nest in a rocky bardo, until waterjets of change come bursting through, pulling us free and into a rudimentary form of consciousness. We gestate in the ocean, maybe even for nine months as we slowly ascend to the icy crust. Working our way through the ice fissures is another stage of the journey, perhaps our adolescence. We gain a body, could it be the trappings of maturity, family and home and community? We live in icy pools, the home of midlife. As an embodied particle we are shot free of the surface into space, the time period of retirement when we are no longer caring for teens or parents or corporate bosses but have to shape the next stage of our destiny. We orbit Saturn, perhaps finding a spiritual community in our final years. As Rilke says, we are orbiting the high tower.

 

Then, ah then, the ionized gases of Saturn strip away our bodies and we are worn down to our nano-particular essence. But our journey is really only just starting. We don't return to the bardo for another round, as some would have it. Instead we frolic in the magnetic fields of our giant god, rising and falling and swirling and dancing for an unmarked eternity.

 

Until... one day the solar wind comes and revs us up to high speed and we shoot out of the known world into the void. That is the afterlife after the afterlife, an adventure beyond even my imagination.

 

What does it mean to make meaning? What does it mean to live a meaningful life? I love to draw out these metaphors, our life as a nanoparticle's journey.