A novelist sent to explore the cosmos meets the people behind the telescope.
Second by second, hour by hour, year by year, it has been ages coming through the cosmological snow, sleet and hail -- 12 billion years of silken light traveling at 186,000 miles a second, all beaming news from the backboards of the universe, the roaring proscenium where time almost began. Eons later, what remains of that early light is a thin mist of photons, a trail so faint when it caroms off the primary mirror of the Hubble Space Telescope, 375 miles up in space, that it is like glimpsing from New York the flicker of a firefly in Tokyo. Photon by photon, however, this ancient light is amplified by a powerful silicon chip known as the charged-coupled device, or CCD. Churning it into digital bits, the CCD then fires the raw image down to earth, where it bounces from a string of relay stations to a long, sleek, onyx-windowed building in a northeastern Baltimore neighborhood. Built into the outcroppings of the hill, without fanfare or antennas, the building's beige bricks might almost be the prow of a ship, vanishing in the gray tangle of winter trees. Across the street sits the Johns Hopkins Department of Physics and Astronomy. As for the beige building, this ship of bricks -- it is the Space Telescope Science Institute, or STScI -- the scientific hub that determines what Hubble will be looking at. In an anywhere, anytime world, STScI is the privileged perch where astronomers are inhaling ever more enormous draughts of the big hereafter. Further excerpts...
Inside the reception area, there is a bit of the theater that might be expected from a NASA-sponsored enterprise. Suspended from the ceiling, looking like a section of sewer pipe fitted with photoelectric wings, is a modest tinfoil version of the school-bus-sized space telescope. Here, too, are spectacular Hubble pictures. Amoeba-like fields of galaxies. Pillars of fire and the jellyfish-like blobs of exploding supernovas, all set off by a monitor showing NASA TV scenes of the space shuttle that in 1997 powerfully improved Hubble's already formidable eyesight with new cameras. After taking in this science-fair sendup, however, I step behind the public face into Hubble's human brain, an expanse of long, iceberg-white corridors, where astronomers taking these postcards from the edge sit by their consoles cogitating and clacking. Peering into an oversized monitor swarming with tiddlywink galaxies, here is a woman with efficient short hair wearing thick, nubby socks with Birkenstocks. And here, slipping by, is a man in a snug tie and sweater vest, carrying what looks like the paper readout of an EKG. It is a spectrograph of the light from some celestial object, a moment long past whose incendiary pops still burn under the eyelids of time like the last acrid puffs of a Fourth of July finale. Light is the thing. Absorbed or emitted by electrons, light to the astronomer is like prehistoric amber, like casks from a wreck, in terms of what it contains and discloses of space's trillion-eyed swarms. Whether the light emanates from stars, galaxies or clouds of gas, its spectral lines can be read like tree rings to determine such things as distance, temperature and chemical composition. Moving down the hall, I pass ponytails, trekking gear, short sleeves in winter. Still, who cares about dress codes when pondering these glory views of creation that Hubble is beaming back? Think about it, pilgrim. What in our time might figure as our Chartres Cathedral or Sistine Chapel? To some degree, the closest thing just might be these exalted electronic frescoes of stars dying and being born. These, perhaps, are our true religious images. Like an organ blast, they bring a hush that distracts us, however briefly, from the flash and chatter of our irredeemably secular age. Still, the monastic quiet of the place has a distinct edge to it. So just who are these ferociously concentrated people? And what would a Magellan or a Lewis and Clark make of this travel without motion and thrill without danger? Granted, astronomy always was a largely cerebral undertaking of telescopes and mountaintops, but with robotic spacecraft, easy-chair science has reached its zenith, transporting our minds -- with growing verisimilitude -- to realms our bodies could not penetrate in a million lifetimes. With Hubble, armchair science is now the frontier. And today this team is undertaking what in the optical realm is arguably mankind's longest, most ambitious journey back to the dawn of time. A Quiet, but Pressured Cloister Here, with some insights, perhaps, is the first officer of this particular expedition. For someone who lately has had very little sleep, and who must keep almost 50 independent-minded Mensa-class intellects reasonably happy and focused, Harry Ferguson looks remarkably cheerful this morning. Other than the cloistered quiet, the first thing I feel is the pressure. In Ferguson's crammed office, he shows me the observing schedule for this latest voyage. Carefully graphed and plotted, it is the 10-day stint that Hubble spent shooting the deepest survey ever of the southern sky -- of any sky, for that matter. Known as the Hubble Deep Field South, it is a mission to assemble and layer from hundreds of images shot in multiple bands and spectrums the deepest, clearest images ever taken of the early universe. It also explains why ambitious colleagues around the world -- all anxious for a crack at the same data -- are peppering Ferguson with E-mail messages and calls. At $60,000 a pop for each 90-minute orbit, each second of Hubble's dance card is so minutely choreographed that even a day's instruction can mean a month of solid planning and programming. Downstairs, in the main computer room, amid icy blasts from the air conditioners that cool the mainframes, two technicians sit at consoles, monitoring the quality of Hubble's daily feeds. As far as "steering" the ship, however, this is carried out in periodic batch feeds of telemetry data from the Goddard Space Flight Center, in nearby Greenbelt, Md. Hubble's daily care and feeding are programmed days if not weeks in advance, with few, if any, surprises. Predictability. Considering that Hubble once ranked among the biggest embarrassments in NASA history, this in itself is an extraordinary turnaround. When the telescope was launched on April 25, 1990, the astronomical world -- expecting to be dazzled by images 10 to 20 times the resolution of earthbound observatories -- instead saw blurs and fuzzballs. Impossible! After $2 billion and 15 years of hands-on development by some of the world's finest scientific minds? And all because the glass -- the heart of any telescope, after all -- was flat by a fraction of the thickness of a sheet of paper? Assembling a blue-ribbon team, the astronomical community and its toymakers came up with Costar, a 5,000-part gizmo that uses an array of tiny mirrors on tiny stalks driven by micro motors to correct for the primary mirror's otherwise fatal flaws. Three years later, when NASA made the repair, the shuttle crew aced it, executing what ranks among the most complex and perfect missions the agency has ever flown. The problem today is producing the kind of images and data that the public and the scientific community now almost routinely expect. Added to the burden is the almost talismanic quality of Hubble, not merely the acuity-terrestrial telescopes can see almost as far -- but the otherworldly clarity and majesty of the images. Consistently hitting this mark comes at a price, however. Typically, the raw images require tremendous work, and this is all the more true of the deep-space images that Harry Ferguson and his cohorts are working on. Operating at the outer limits of Hubble's acuity, the Deep Field images Hubble returns are at best intriguing chaos -- Jackson Pollacks, scribbled with machine signatures and cosmic rays. Somebody, then, has the task to scientifically pick the best parts -- best pixels, rather -- from all these duplicative images, then to cook the data down into scientifically defensible results that their colleagues cannot pick apart. What you need, above all, is someone skilled in data reduction, part mathematician, part computer jock, part surgeon. "It's not that we want to merely see farther and farther away," Mark Dickinson explains showing what -- to my eye, anyway -- is already a fairly sharp draft image. "For us, the real goal is to see farther back in time, to the universe as it actually appeared billions of years ago. Think of it as Jurassic Park for early galaxies. Not fossil remains, but the actual galaxies themselves. Billions of years later, you can still see the dinosaurs out there grazing." But what a mammoth undertaking. After "dithering" the three cameras -- shooting a dizzying mosaic of views -- the shots, in a puzzle that might have even God tearing his hair, must all be layered and stitched back together, and then to better than the width of a pixel. The work of electronically registering and scouring these images is more than mere esthetics, however. With swarms of galaxies, many smaller than pinheads, even a few errant pixels can contaminate or hopelessly compromise the critical galaxy counts that scientists need to accurately determine the density and evolving structure of the early universe. These guys love folksy analogies -- so long as the analogies are their own. This is like joking in church. The priest tries to come down off the mountain. We, for our part, try to talk up to the mountain, but still it is a stretch, and for the neophyte, there is no way to conventionalize it without betraying either ignorance or anxiety, as much in the face of the daunting science, as in what these images force us to radically reconsider. Time and space. Mortality. Indeed, our own puny human claims on significance. How new all this knowledge is. And how rapidly the chase is narrowing. Breaking Paradigms While Breaking Bread It's kind of a lunchroom Last Supper scene. Surrounded by some of the team's key members -- Dickinson, Ferguson, Stefano Casertano from the European Space Agency, Andy Fruchter, and Jonathan Gardner of Goddard -- the leader of this expedition is sitting in the STScI cafeteria. This last Bob Williams stirs with great deliberation, bringing the fruity contents up from the bottom, much as he explains to me that in the universe, too, it seems to be a bottoms-up phenomenon. For decades, this was one of the more vexing questions in astronomy: bottoms up or top down? In explaining this eternal dance of energy and gravitation, the top-down view held that the big clusters formed first, then fragmented into smaller galaxies. Conversely, the bottoms-up view saw the "smaller" fry gathering more material over time to form larger galaxies. As Williams explains, the Deep Field shows pretty clearly that it is bottoms up, all for the simple reason that these early galaxies are so much smaller than any we would see closer by -- closer meaning nearer in age. And just how small are these galaxies? I ask. "Oh, these guys maybe 3,000 light years across," he replies. "Say, maybe a 10th the size of our Milky Way." Until September 1998, when he resigned to return to pure astronomy, Williams was the director of STScI. It was Williams who in 1994 dreamed up the original Hubble Deep Field when he trained Hubble's eye on another equally insignificant hole of sky to the north. Dubbed the Deep Field North campaign, this was a first, a true "core sample" of the universe, as he puts it. At 58 Williams is another turtleneck wearer, a long-distance canyon runner and a smiler -- all in all, a true Californian, with the mettle of a general and the manner of a country doctor, at least when dealing with the science laity. Laid back as he is, it is curious how, without directing, Williams nonetheless directs, a master of the strategic pause. Precious Minutes, Pinpoint Views Each year astronomers around the world submit proposals to the Time Allocation Committee, vying for a few 90-minute orbits or, perhaps, several full days if they walk with the angels. In 1995, at the time of Deep Field North, there was no precedent for anyone to get a full 10 days. Hubble focuses on a viewing hole the size of the period at the end of this sentence -- a point that, 12 billion light years away, disgorges a cornucopia of galaxies seven million light years across. Williams says, "What the Northern Survey showed is that early galaxies were a lot smaller, and more amorphous, than the spiral and elliptical shapes that we see in more nearby galaxies. And again, we see that galaxies got bigger over time -- in other words, confirmingthe bottoms-up view of smaller galaxies merging to form the bigger guys. Finally, we see that galaxies did not form right after the Big Bang, but built up steadily over seven or eight billion years, or at a time about half the age of the present universe." Three days later, just a few days before Thanksgiving, the call comes, and we all pile downstairs. The images they plan to make public are ready. Final inspection before they go to the printer. From that thistle of light poked into the southern cosmos, Hubble disgorges as many as 3,000 galaxies, each holding billions of stars, which by now have long since burnt to cinders or collapsed into world-swallowing black holes. As I ogle over the jammed shoulders of the astronomers, there is for me an "Alas, poor Yorick" quality to it, a sense of staring into the darkened recesses of your own cranium. Finally, you hit a wall, for it is not enough merely to look. For this you must forcibly imagine. Yet almost inevitably, they spot a problem, the heavenly detailers of STScI. The red and the blue are not aligned, leaving all but imperceptible halos around the galaxies. So madcap, fast-talking Andy Fruchter, master of the arcane art of "drizzling" -- to restitch the image after all this dithering of the cameras -- well, Fruchter has some work to do, using a custom program that he and an English counterpart named Richard Hook wrote. Talk about slick! With hair's-breadth precision, the program subtly shifts and rotates the image, all while misting it over with pixels. When the Deep Field goes public a few days later, it gets some nice coverage. Still, there's one last hump for STScI's sedentary Sherpas. Just after New Year's -- after another month of trouble-shooting while they write their own papers -- the core team flies to Austin, Tex., this for the big roll-out at the biannual American Astronomical Society convention. Yet here while they have killed themselves getting the data right, they have given remarkably little thought to the press conference. In the restaurant, they divvy up their talking points. Meanwhile, Ferguson, Dickinson and Gardner are punching hand calculators, figuring at the last possible moment the number of galaxies in the universe, all as extrapolated from the counts of this unfathomably large but finally miniscule garden patch. Jonathan Gardner is first. Up he gogs, blinking. "I get 125 billion," he says. "Yep, me too," agrees Ferguson. "Let's go." Eagerly Looking Beyond The press conference goes well, so that night, with two colleagues, Ferguson and most of the team celebrate with a late-night Mexican dinner on Austin's main drag, honky-tonk Fifth Street. Heads down, talking, they are like seminarians on holiday, seemingly oblivious to the circus atmosphere of vampire punks, phony cowboys and blood blister-colored low-riders. Finally, in an agreeably empty Mexican place, nursing cervesas and margaritas, the STScI druids talk about -- what else? -- the telescopes and probes they would like to fire into space. It suddenly hits me, they really are rocket scientists. They really are rocket scientists. Look at them, I think. They could be making a fortune, plotting new derivatives or taking some high-tech company public, but here they are shoulder to shoulder in the whaleboats, pursuing the ultimate questions. Where did we come from? Where are we going? In the Hubble Deep Field South, the good news, strangely enough, is that data is not contradicting what we found in the first deep field. This is very reassuring about the basic tenets of cosmology. It shows -- despite the fact that we need to keep testing these assumptions -- that we really do seem to be on the right track. On another level, it's that epiphany when you look up and see, on some level, that you're really connected -- connected like a child to all these wonders up in the sky." And maybe astronomers are justified in their optimism about answering the big questions in the next 30 or 40 years. It seems that perhaps we are truly witnessing astronomy's golden age. I can imagine how mariners in Columbus's day once feared sailing off the world's watery edge, into the yawps of monsters. Only now, it seems we sail on the other, equally slippery side of the world, a time where we fear not life's unknowns, but rather the driving beat of its gathering knowns. Click the mouse and out it comes, pilgrim -- 12 billion light years. Eternity itself. All on demand, like water from a tap. |
