Exoplanets

Something truly amazing happened the other week. I am not referring to Ed Koch being buried in the Trinity Church Cemetery in Upper Manhattan (regarding which I have nothing to say, or rather nothing I wish to say out loud), but to an event that happened, of all places, in Long Beach, California, at the annual meeting of the American Astronomical Society, when scientists from the Harvard-Smithsonian Center for Astrophysics in Cambridge came to town to report on their analysis of data retrieved from NASA’s Kepler Space Observatory. 

The Kepler Observatory, launched in March of 2009, was sent into space specifically, to quote the NASA website, “to survey a portion of our region of the Milky Way galaxy…to determine how many of the billions of stars in our galaxy have [earth-like] planets.”  That sounds like a reasonable thing for NASA—and for humankind—to want to know, and the results have been, to say the very least, astounding: since the mission began almost four years ago, Kepler has located an amazing 2,740 planets orbiting 2,036 stars.  That alone would be more than impressive—especially given that just a a few decades ago, no planets at all outside our solar system were known to exist—but the truly amazing part has to do with the way scientists at the Harvard-Smithsonian Center for Astrophysics in Cambridge have managed to use the Kepler project's data to extrapolate that, in their very learned opinion, there must be "at least seventeen billion" Earth-sized planets in our galaxy alone. That’s a lot of planets! And they are rotating, so this montah’s announcement, around approximately 17% of the approximately 100 billion stars in the Milky Way. 

To say the same thaing in different words, that means that scientists now estimate that there is an earth-size planet rotating around one out of every six stars in the galaxy. (To be exact, by “earth-sized” they mean somewhere between 85% the size of the earth to 1.25 times larger as our planet. If planets more than 1.25 times the size of the earth—the so-called “super-earths”—are included, the number is even higher.) Interestingly, the stars around which these earth-like planets are rotating are not all similar to our sun. In fact, many of these planets—technically called exoplanets, the name for planets outside our solar system—are rotating around stars called red dwarfs, which are both smaller and cooler than our sun. (The importance of that thought is that a planet “like” earth could rotate much closer to such a star and still have surface temperatures within the range deemed compatible with life, or at least with life as we know it.  If you are reading this electronically, click here to see all sorts of graphics posted at www.space.com that make all these numbers dramatically easier to digest.) 

I’ve always been a great fan of the American space program. Alan Shepard became the first American in space just a few weeks before my eighth birthday. I was twice that age, sixteen, when Neil Armstrong took his first steps on the surface of the moon. (I know exactly where I was too when he took those steps: lying flat on my back on a blanket in a field in Burlington, Vermont, looking up at the moon and trying to figure out how long before I was hearing his words on my tiny, tinny transistor radio they had actually been spoken on the moon. I also remember whom I was lying on that blanket next to, although I’m not sure exactly what became of her since.) I even remember being a summer-school student at JTS in the summer of 1976 when the Viking 1 lander set down on Mars and almost instantly started sending back color photographs of the Martian landscape. And, of course, I also remember being in my office in Heidelberg in January of 1986 when I heard that the space shuttle Challenger had blown up almost upon take-off, just as I remember being in the middle of my first year at Shelter Rock when the Columbia disintegrated over Texas in 2003.There is a sense out there, I think, that rabbis—and probably clergy people of all faiths—are supposed to be at least slightly unnerved by science or at least wary of the implications of its boldest theories and discoveries.  

But that basic assumption—that faith and science are basically incompatible disciplines, and that we can only truly embrace one if we are prepared to ignore the implications of the other—has never been especially resonant with me. I feel confirmed in my faith, content with believing what I feel called upon to believe and actually do believe about the world, about God, about the nature of religion and, particularly, the nature of my own religion as it exists in the physical world…but also fully open to the discoveries of modern scientists not begrudgingly but openly and enthusiastically. I have always felt uncomfortable with the so-called “two truth” theory whereby scientific truth and religious truth are deemed simply to exist in different universes of discourse, thus obviating any need for them to be reconciled at all! And more than just uncomfortable, to speak more honestly: all truth by definition being congruent with all other truth, the divide-and-conquer approach to science and faith seems to me disingenuous to the point of being false. Yet the world seems certain that science is enemy of faith!

It was with these thoughts in mind that I read Jonathan Sacks’ latest book, The Great Partnership: Science, Religion, and the Search for Meaning, published last year in the U.S. by Schocken Books. Sacks, the outgoing Orthodox chief rabbi of the U.K., seems as enthralled by science as I am, and as little inclined to accept as reasonable the notion that to be a person of faith means, ipso facto, that one has to deny the veracity of the great discoveries of science or, at the very least, to ignore them. The chief rabbi writes with passion and with great intelligence about his own journey to faith, but also about his life-long love of science and scientific writing. Much of what he writes will strike readers—or at least North American readers familiar with the Jewish world as it exists in our place—as surprisingly inconsonant with the views and attitudes generally associated with Orthodoxy. But here is a man who writes with fire in his belly about something he appears truly to believe, as do I: that the notion that religion can only exist where science is ignored basically means that religion can only truly be embraced by naïfs who live in a make-believe world of their own making and must therefore be rejected—and rejected firmly—by people who wish to remain equally committed both to intellectual and to spiritual integrity.  I recommend the book to all of you. It is smart, extremely well written, and challenging in a healthy, provocative way. I liked it, and I think you all will as well.

But what about all those exoplanets? If the people from the Harvard-Smithsonian are right, there are seventeen billion planets in our galaxy alone that are “earth-like.” Clearly, most are incapable of supporting life as we know it. Perhaps they cannot support life at all…but surely within all those uncountable planets there surely could be one single one on which life developed in a way analogous to the way it did on earth.  Tau Ceti f, a mere 11.9 light years from here, orbits a sun-like star and has an Earth Similarity Index of 0.71. (The Earth Similarity Index is based on the degree to which a planet’s surface is like the surface of earth and the parallel degree to which its atmosphere and weather are similar. Mars, for example, has an ESI of 0.66, Venus a mere 0.44.) Further off, super-earth Gliese 667C c has an ESI of 0.85, the highest of any known exoplanets. If it turns out that KOI1686.01, discovered tentatively but not yet conclusively by Kepler, actually exists, it is expected to have as its ESI an astounding 0.93.  You get the picture. Almost definitely, we are not alone.Didn’t we always sense that? Looking up at the nighttime sky, we see the tiniest fraction of what’s really out there…and yet the stars that we can see even without a telescope feel innumerable.  Contemplating the possibility—what now seems in light of these latest announcements, the overwhelming probability—that there are other planets out there on which have evolved life should be unnerving. 

What does that say about the creation narrative in Genesis? Where does that leave people who wish to imagine that human life on earth is the pinnacle of God’s creation? What if the residents of Gliese speaks about the special destiny of their people to bring redemption to the universe, or at least to their own planet? I suppose the answer to all of those questions depends on us as much as on the data itself. Will we respond to the discovery of extra-terrestrial life in the manner of enraged children overwhelmed by the discovery that their father also has some family in Peru or Tasmania or Mallorca that he’s been living with on all those business trips abroad he always claimed to need to be making, including children who miss him when he’s on what they think of his endless business trips to here?  

Or will we find in the discovery of life elsewhere in the universe the context finally to grow into the state of abject humility that our sages suggest is the requirement not only for knowing God, but even for knowing of God. The prophet Amos, probably because his book is so short, doesn’t get enough play, but he was one of the greats. Living in the eighth century B.C.E., he too faced a people in love with their own importance and, particularly, with their own uniqueness and it was to them directly that he addressed some of the most famous rhetorical questions recorded in the Bible. God, the prophet says, appeared to him at the side of the altar in the Temple to charge him with bringing a truly remarkable message to the people. The greatest enemy of faith, God taught him, is arrogance and unearned pride. To find, therefore, in the story of Israel’s deliverance from bondage in Egypt “proof” that no amount of poor behavior will ever alter God’s ongoing commitment to preserve and defend the people is, the prophet learns, the definition of supercilious foolishness. “I took you forth from Egypt,” Amos is told to say in God’s name to Israel.  That much is true, but do you imagine that I care more for you than for, say, the Ethiopians? I brought you forth from Egypt, yes…but did I not also bring forth the Philistines from Kaftor, and the Arameans from Kir? You never heard of those places? Well, the faithful of those nations probably don’t know much about My role in your history either! But to imagine that God’s involvement in the history of your people somehow precludes God’s involvement in the history and destiny of other nations—that is the kind of arrogant nonsense that leads away from, not toward, the embrace of destiny in the context of faith.It’s a great passage. (You can find it easily in the ninth chapter of Amos, the last in his book.) And it should suggest the right way to respond to the announcement in Long Beach last week.  

To contemplate the universe in its fullness—and that, only to the extent to which we are currently capable and certainly not in any ultimate way—should inspire not despair but the deepest humility.  What we know of the world is the tiniest part of what there is to know. What we know of the universe—including its uncharted reaches that lie so far beyond our own galaxy that we cannot even properly imagine what it is we know nothing of—is barely what a newborn knows of the world in its fullness and richness.  The enormous strides forward we have made in the last decades will eventually be derided as the tiniest of baby steps forward towards understanding our place in the universe. And yet…instead of finding all of this threatening or upsetting, I find it, if anything, ennobling and humbling. I feel the truth of the creation story not in its details, but in the satisfying thought that the unimaginable complexity of creation actually does mirror its unknowable Creator. And I think that is the right way for all thinking people of faith to respond to the astronomers’ report not of hundreds or thousands, but of billions of planets out there…Earth among them to be sure, but also (the ones I’ll call) Kaftor and Kir…and (the one the world calls) Tau.