Could it Zero in on Enceladus?

Some years ago I wrote a planetarium show for the Springfield, Massachusetts facility about the search for life in the universe. The show, which Mark and I sell through Loch Ness Productions, is called Oceans in Space. In it, we talk about the formation of life on our planet, and then look around the solar system for other places where the basic needs of life (water, warmth, organic material) could be met. We implied that some of the frozen water worlds of the outer solar system, like Europa, for example, could be considered as likely places where life might get a foothold.

Another world often discussed as a possible life-bearing place is Enceladus, one of the larger Saturnian moons. It shows a number of different kinds of surface units (five terrain types, if you will), including areas that are clearly recently resurfaced from within. That means that something is heating Enceladus from within, forcing fluid to ooze out over the surface (or, possibly as ice geysers) and refreezing (which would cover up any craters or cracks that existed there).

Since heat is one of the “feeders” of life, and there’s heat generated inside Enceladus (likely from tidal heating caused by gravitational squeezing), and there seems be water on (and in) Enceladus, it would make sense that life could exist on (or in) that moon, provided that life had some sort of food (chemical or biological) to feed on.

Well, as it turns out, Enceladus may not be as water-rich or hospitable to life as scientists thought. New models of this moon’s interior, based on data supplied by the Cassini spacecraft in orbit in the Saturn system and discussed in this press release, suggest that maybe what we’re seeing on this moon’s surface may not be driven by the action of liquid water inside the moon. Instead, it might be caused by what researchers call the “dissociation of clathrate ices.” Clathrates are ice compounds in which one kind of ice (say, water) is imprisoned in a matrix of another kind of ice (ammonia or methane, for example). In this case, Enceladus may well have a heat source that only needs to heat the ice a little in order to melt the ice shell. The release of some gases in the process would be enough to send plumes of material out and re-coat the surface. This may mean that there’s less water on Enceladus than scientists previously estimated.

This isn’t a kiss of death in the search for life in our solar system. It just means that one of the main components necessary to help life along on Enceladus isn’t so abundant, making that moon less hospitable to life.

What I like about this story is that the finding IS a confirmation that the observations we’re making over the long term in the outer solar system are teaching us about the mechanisms that shape those worlds, including the roles of other chemical and geological processes in icy worlds. And, just because those worlds MIGHT be able to harbor life doesn’t mean they actually HAVE life—a distinction that I rarely see made in media reports about the search for extra-terrestrial life. It’s one thing for a world to have the capability to sustain life (or even have the conditions where life could form). It’s quite another to actually prove that life exists there. To do that, we have to see the life and we have to understand the complex chemical and geological conditions that exist there.

When I was a little kid I thought the astronauts were THE coolest people alive. They got to go out into space, fly nifty spacecraft, and visit the Moon. I followed all the missions on TV, and once for a science project, I built an Apollo spacecraft with my dad. Sure, it was cardboard and wood, but it was MY spacecraft. I wanted to go out into space; still do, actually. But, for a variety of reasons, I’m a science writer and not a space astronaut, although I still do dream of going into space. Maybe someday…

I still think astronauts are among the coolest people I know. There are a lot more of them since I was a kid, and they aren’t all fighter pilots anymore. Many are scientists and mission specialists and teachers (yeah, how ’bout that teacher in space, eh?). I’ve even met a few astronauts over the years, and it’s nearly always been a pleasure to talk with them.

For the past few weeks I’ve been listening to a talking books version of astronaut Walter Cunningham’s book The All-American Boys.* It’s a pretty unique look at his experiences as an astronaut, along with some bracing commentary on NASA’s culture and evolution. I’m still working my way through the CDs (it’s a 22-CD set!), but it’s been quite inspirational so far. I’ve learned a great many “I didn’t know that” facts, such as the fact that in the early 1960s, an astronaut’s pay was around $13,000-$15,000 a year! Sounds like nothing now, but back in that time, it must have looked fantastic—and, you got to play with cool toys and go into space. What was there NOT to like? Plenty, as we learn in the book.

Cunningham does the reading, and at first I felt like I was listening to a pilot do the reading, what with the laconic style. But, behind that sometimes-deadpan delivery is a riveting story of what it was like to be selected as an astronaut in the mid-60s and an often-critical look at culture of his employer (charged with getting an American to the Moon before the Russians could do it). Even when he’s describing the unique (and apparently wart-filled) NASA culture of the time, Cunningham comes across with some very inspirational insights about what it takes to fasten on to a goal in life and then do everything you can to attain it.

So, listening to Cunningham describe his experiences brought me back full circle in my admiration of astronauts (and I plan to visit this theme a bit more when I write the full review of his book in a week or so, so stay tuned). We all have our heroes in life. Mine happen to include (but the list isn’t limited to) astronauts. Perhaps it’s a remnant of that period in my life when astronauts were the most public part of the mechanism that gave us the space program. I know that those guys (and a few women) who have gone into space are most definitely human beings behind that “hero” facade. Of course we all know about the astronauts who (like other human beings) make mistakes, very publicly. But, that doesn’t diminish what it took for most astronauts to help their countries achieve space flight and exploration.

There’s a valuable lesson to be learned in talking to (or listening to) astronauts, just as there’s one to be learned from honest, fair, and successful astronomers or doctors and others who have achieved great things in the sciences. Our future lies in the hands of these folks who explore and dream and achieve things that move humans forward (and not backward, as we are so painfully learning in the U.S. today).

*(Full disclosure: Cunningham’s publisher sent the CD version of his book to me for possible review on this blog.)