The Canon (42 page)

We live on a Goldilocks world, taking the jackpot trail through the solar system. Go one planet closer in, to Venus, and temperatures average 900 degrees Fahrenheit. Jump out a groove, to Mars, and it's—75 degrees. Earth is just right for life, and life has clung to its skin for more
than 3 billion years, if sometimes just by the skin of life's teeth: 99 percent of all species that have ever lived have gone extinct. We humans may be exceptionally highhanded and ham-fisted in our Earthly transactions, but Earth and its life are much bigger than we, and they'll carry on whether we do or not. Maybe we need to get away from it all, take the ultimate off-road vacation to a celestial location. It's time for the populist stage of the Space Age, and the family-budget space flights we've been expecting since NASA gave us Tang. Everybody deserves a chance to experience the great awakening that clearly comes with extraterritoriality. Astronauts have attested to it time and again, the transformative moment when they first looked down on the oneness of bright blue marble Earth, their only home, and Earth looked back and said,
I know.

F
OR MANY OF US
, the most memorable books, poems, and cautionary doggerel of childhood all had something to do with astronomy. We learned to wish on the star light, star bright, of the first star we saw that night, and we were incidentally saddled with lasting confusion over the precise semantic distinction between "I wish I may" and "I wish I might." We were asked whether we'd like to "swing on a star" and be better off than we are, or would we settle for life as a dirty, illiterate farm animal with disgraceful shoes. In the proxy of a rabbit wearing striped pajamas, we bade, "Goodnight, Moon," and goodnight, cow jumping over the moon, and goodnight, bears and chairs, stars and air, brush and mush, and, you, too, old lady, whispering "hush," and who are you, anyway, and how did you get into my great green room?

Even growing up in the Bronx, where any twinkling lights one might see overhead most likely belonged to a police helicopter, I had celestially themed dreams. In my favorite, I dreamed at age five that my family was vacationing in the country, and somebody called me to come look at the Milky Way; and when I ran outside and gazed upward, the heavens burst into tinkly music like that of a Mister Softee truck and drizzled me with milk. What a simple, joyful dream it was, and what luck that I wasn't a bed wetter!

We are all of us starstruck from the start, mesmerized by the spangled velvet of the nighttime sky, now longing to pull it close, like a mother, now shrinking beneath its inviolate diamond detachment. Soon we are able to pick out at least a few of the easier constellations—certainly the Big Dipper, maybe the Little Dipper, too, and boxy Orion
with his bright belt and sword, and the five-star zigzag of Cassiopeia. We learn to distinguish between stars and planets by whether they twinkle or shine, for stars are so distant that they appear as mere points of light in the sky, and that light is easily bent and bobbled by turbulence in our atmosphere, while the planets are close enough that their radiance passes through air with scarcely a diversion or refraction, and so planets will bluntly, unwinkingly shine. Indeed, with an ordinary backyard telescope and under the right conditions, you can see the cheeky spheroid faces of our siblings in the solar system—Jupiter and its red spot, which is really a giant gaseous hurricane big enough to engulf three Earths and which has lasted for at least four hundred years; Saturn and its hallmark Hula-Hoops of ice, dust, and rock; tangerine Mars and moon-white Venus. But even our most powerful telescopes cannot resolve the disk of an extrasolar star, no matter how massive the star may be; all stars are too far away to be sized and analyzed as anything but points of light.

We stare and stare at the night, looking for something, anything, to make sense of the thundering silence—voiceover, pantomime, anagram, Vulcan mind-meld. Can't you just say something? Don't you hear us? Here we are! And as we stare, we see a streak of light, a wild platinum cat scratch piercing the mute tuxedo screen, and we're thrilled, each time, and filled again with goofy hope. A shooting star! I saw a shooting star! Did you? Well, just keep looking. You'll see one, too. Oh, we know they're not stars. They are meteoroids, space debris, the bits of interplanetary rock with which our solar system is littered; and though most of them are quite small, no bigger than a marble, they careen parabolically through space at such high speeds that when one of them hits Earth's atmosphere, the force of friction sets the rock ablaze, and Earth-bound viewers for thousands of miles around can watch the combusting rock bid us all a bright good-night.

With their tragicomic displays delivered in live-stream feed, meteors are especially easy for us modern humans to love and humanize, yet as Earth makes its squashed circle pilgrimage around the sun, the other stars and planets also appear to march across the nighttime sky. And the moon, as it wheels around Earth, swells and shrinks and swells again, not randomly, not like a yo-yo dieter, but in meticulous clockwork slices. The ancients missed not a trick or a tock. Like our nursery jingles and semiotic bunny board books, the earliest artifacts of civilization highlight our long-held fascination with the lights on high. Some 35,000 years ago, a sculptor-skywatcher living in what is now the Lebombo Mountains of southern Africa carved twenty-nine evenly
spaced notches into a baboon bone, each groove likely representing a phase of the moon. Other artisans of the Pleistocene left behind similarly tooled eagle bones in sites not far from the famed Lascaux cave paintings in France. Ancient Chinese scholars engraved astronomy charts in bones and turtle shells, recording the paths of stars and planets and identifying hundreds of constellations. The dour megalithic monument of Stonehenge and the Mayan city of Palenque are thought to have served as astronomical observatories, their structures aligned to make dramatic use of the sun's light on the summer solstice, a sacred day in many cultures. For our seven-day week we can thank the ancient Babylonians and Greeks, who carefully observed the behavior of the sun, moon, and five quirky "stars" that we now know to be planets—the five planets that can be seen with the naked eye and that are so comparatively close to us they fairly glide across the sky, noticeably shifting their position against the stellar backdrop from one night to the next. (The word "planet," in fact, stems from the Greek word for "wanderer.") The seven heavenly standouts were named for the reigning deities of the era, and since every god must have its day, the names of the days followed suit. The Roman Empire and its Germanic outposts changed the names of the Greek gods while leaving the basic tenets of the pantheon intact; and though the Anglo-Saxon renderings of the deities can obscure some of the connections in English between the names of the days and of their heavenly projections, if you have even a smattering of familiarity with a Latinate language like Spanish or French, you can piece the little celestial-seminal puzzle together. Sunday is Sunday. Monday is Moonday. Tuesday in Spanish is
martes,
so Marsday. Wednesday,
miércoles,
or Mercuryday. Thursday is
jueves,
which, by Jove, is Jupiterday. Friday, or
viernes,
is Venusday. Saturday is Saturnday, my favorite day, a day for the unrestrained revelry of a saturnalia, or the protracted gloom of the hopelessly saturnine.

Throughout the ages, those who were wise in the ways of the skies were regarded as high priests and sages, petitioned for guidance on when to plant crops, woo a lover, launch a voyage, invade a country. In the predictable procession of the stars across the cosmic dais, people saw signs of divine intent, of a structure and certainty otherwise absent from their lives. Down on Earth, who could say if tomorrow would bring feast or famine, lockjaw or locusts? Up above, you knew that come the next spring, Virgo the Maid would appear in the southeastern sky. Humanity's fate was seen as bound up with the stars, a conviction yielding both the fantastical nostrums of astrology and the birth of the global economy. By setting their sights on the steady wink of Polaris,
the star of the north, early traders could traverse the most pokerfaced seas and still find their way home in the dark.

Astronomers today may no longer be counted among the cultural clergy, and sometimes they complain about being comically misunderstood. "I don't do horoscopes, and I am not a failed astronaut," said Alex Filippenko, an astronomer at the University of California. Yet in the main, astronomers are among the most admired and beloved of scientists, and they know it and they like it. "We enjoy considerable public appreciation, and we get more than our fair share of press," said Chuck Steidel, a professor of astronomy at Caltech. "I'm always amazed at how I can go to my doctor or dentist, and they'll have a long list of questions for me when I arrive.

"Compared to something like high-energy physics," he added, "I'd say we have it really easy."

Astronomy is so easy to love. It is filled with outrageous magic that also happens to be true: novas and supernovas and pulsar stars that spin and click and are as thick as an atomic heart, as thick as Joyce's Muster Mark; and those thicker, darker collapsed star carcasses we call black holes, which are so dense that even light cannot escape their gravitational grip; and quasars, celestial furnaces at the edge of the known universe that are the size of stars but as luminous as entire galaxies; and theoretical plausibilities like extra dimensions beyond the four we know, or the creasing of space-time into shortcut "wormholes," which, if they exist, would be the equivalent of time-travel machines. Astronomy is about the heavens, the divinest of final frontiers and the presumed zip code of Ra, Vishnu, Zeus, Odin, Tezcatlipoca, Yahweh, Our Father Who Art In, and a host of other holy hosts; and that religious resonance markedly broadens the discipline's appeal, making it feel both cozier and more profound than it might otherwise. Astronomy also seems chaster than other sciences, purer of heart and freer of impurities, mutagens, teratogens, animal testing. Fairly or not, physics is associated with nuclear bombs and nuclear waste, chemistry with pesticides, biology with Frankenfood and designer-gene superbabies. But astronomers are like responsible ecotourists, squinting at the scenery through high-quality optical devices, taking nothing but images that may be computer-enhanced for public distribution, leaving nothing but a few Land Rover footprints on faraway Martian soil, and OK, OK, maybe the Land Rover, too. Astronomers are pure of heart and appealingly puerile. They look into the midnight sky and ask big questions, just as we did when we were in college: Who are we? Where do we come from? And why are we standing around outside on the night before
finals, do we want to end up making elevator parts for a living like our father or what? Astronomers no longer have to worry about finals, although they do have to worry about getting their grants financed and their new telescopes built or at least not have the budgetary plug pulled on their old telescopes. In any event they are professional philosopeepers, and they ask the big questions about where we come from and what we are, and, much to their amazement, they have found answers to those questions swinging from the stars. Of the many extraordinary findings in astronomy over the past half century or so, space scientists cite two as cosmic standouts: the discovery and elucidation of the Big Bang that rang in our universe and the surprising centrality of ancient stars to the rise of life on Earth.

We may associate astronomy with the night and darkness, but one of the core truths of the discipline is its near complete dependence on light. "For astronomers, the universe is our laboratory, and the way we analyze what's going on in that laboratory is by analyzing light," said William Blair, a professor of astronomy at Johns Hopkins. "With rare exceptions, like the occasional asteroid or meteorite, we can't get our hands on the stuff we're studying, but we can learn a tremendous amount about the objects that are out there by examining the different types of light waves those objects emit, across the electromagnetic spectrum. This is one of the little details about the field that I don't think most people are aware of: that almost everything we've come to understand about the universe we have learned by studying light." Recall that optical light, the light waves that fall in the so-called visible range of the electromagnetic spectrum—the light that blinks back at us when we gape at the sky—represents a tiny segment of the light waves that astronomers study. They have designed a battery of bionic eyes capable of detecting virtually every radiant signal the firmament has to offer, from ultraviolet light through X-rays and out to the histrionics of high-energy gamma rays on the short end of the scale; and from infrared radiation, down into the misleadingly named microwaves, and over to the really lo-o-ong energy humps of radio waves. If you happened to see the 1997 movie
Contact,
in which Jodie Foster played a brave young astronomer battling genuinely astronomical odds and a generically asinine bureaucracy in her search for signs of extraterrestrial civilizations, you would have caught a few glimpses of the legendary Arecibo radio telescope built right into the mountainside of Puerto Rico. It's a huge telescope, 305 meters, or roughly 1,000 feet, across, and the diameter of the dish is a measure of just how wide are the radio waves it is set to sample.

By surveying the skies with instruments tuned to every possible wavelength of light, astronomers get a sense of what sort of cosmic bestiary we live in. Infrared telescopes can peer through the thick dust clouds that serve as a galaxy's stellar nursery and detect signals from embryonic stars within. Ultraviolet studies illuminate the nature of hot young massive stars, cool old dwarf stars, active galaxies, and hyperactive quasars. With X-ray and gamma-ray scans, scientists have probed black holes, pulsars, supernovas, and the mysterious gamma-ray bursters, thought to be an unusually violent class of exploding stars. Radio waves murmur hoarsely of the Big Bang from which all else sprang.