The Man Behind Hubble

The Man Behind Hubble

Four weeks after space-walking shuttle Endeavour astronauts repaired the Hubble Space Telescope in December 1993, an ecstatic Maryland Senator Barbara Mikulski waved a Hubble picture of the core of the spiral galaxy M100 at her naysaying colleagues. Today, Mikulski could host a Capitol Hill star party: The orbiting telescope has generated more than 100,000 photos of celestial objects, including a cemetery of dying stars, elephant trunks of dust and hydrogen gas twisting in the Eagle Nebula, jovian storms and aurorae, the rocky rings of Saturn and the colossal supernova smoke rings blown from an exploded star, to list a few.

Hubble’s pictures do double duty not only as congressional lobbying props, but also as screen savers, T-shirt prints, calendar photos, a background for the “Babylon 5″ science fiction TV series and even planet trading cards to be provided soon to schoolchildren. One of the most electrifying pictures of all, the Hubble Deep Field image began literally as a shot in the dark: the sum of 342 exposures taken with Hubble’s Wide Field and Planetary Camera 2 in December 1995 of a black speck of northern sky. Although the Shoemaker-Levy 9 comet impact on Jupiter may have generated a bigger media splash, astronomers still are agog over the Deep Field.

Aides to Vice President Al Gore ordered a Deep Field poster from the Space Telescope Science Institute (STScI), which manages the Hubble’s science program under contract with NASA. Borrowing a page from Mikulski, Gore plans to use the Deep Field poster to promote scientific research in the next millennium. In an age of cost-cutting and smaller-is-preferred, the $3 billion Hubble has demonstrated that bigger can be better: The telescope attracted 1,298 proposals for observing time during its next annual cycle that began in July, an increase of 30 percent from the previous cycle and more than had been received by any other U. S. telescope or NASA project. Ever. A driving force behind Hubble’s scientific mission, particularly the Deep Field, is astronomer Bob Williams, 56, who took over as director of the STScI a few months before the 1993 repair mission. Like Hubble itself, Williams began his astronomy career with high promise, then was written off as lacking focus. Both have rebounded spectacularly. Williams is admired as an articulate champion of astronomy with a penchant for accomplishment.

There is not a devious molecule in his body,” says Ray Weymann, an astronomer at the Carnegie Observatories in Pasadena, California, who spent many nights collaborating with Williams in the quiet and darkness of telescope towers. In graduate school at the University of Wisconsin, Williams excelled as he did as an undergraduate at Berkeley. At Madison, he became an expert on the Crab Nebula, a wispy, cloudlike creature that has been expanding since the supernova of A. D. 1054. He was enthralled with an analysis that he developed, the first of its kind, of the ionizing radiation coming from the nebula’s glow.

There are a lot of properties that one can deduce about the nebula from the characteristics of that radiation,” says Williams. He agrees that the Hubble pictures of the Crab Nebula as well as the many mysteriously varied shapes of planetary nebulae are “beautiful. ” But he, like most astronomers, is more rapt when he discusses their spectra: “By looking at the signature of wavelengths of radiation that are emitted or absorbed by the nebula, you can infer things about its chemical composition, size, density, and temperature,” Williams says with an almost religious fervor in his voice. “That is what spectroscopy is all about.

What else is Williams all about? To get an inkling, I talked with him for hours, speed-walked to meetings with him for two days, and listened in on his conversations inside the STScI, a brick beehive of science buzzing on a forested corner of the Johns Hopkins University campus in Baltimore. Williams’s handshake was muscular and slightly bony. His slender face could have been mistaken for a minister’s — quick to smile and ever relaxed.

A fleet-footed athlete since growing up on the ballfields of Ontario, California, Williams has remained thin, almost gaunt, from decades of running 26. mile marathons, bicycling, and mountaineering. His forehead was scarred from two recent surgeries to remove skin cancers that he attributed to decades of sun exposure while running without proper sunblock protection. The cancer might have developed from running the Grand Canyon, rim to rim, three times, the fastest in three hours and 40 minutes: “That was faster than I could drive the car around, going 90 miles an hour at times,” says his wife, Elaine Williams, a pediatric psychologist.

When he played intramural baseball during graduate school, Williams was known to stretch singles into doubles. At the four-story main STScI building, Williams avoided the building’s indolent elevators and bounded up and down its concrete stairways. Williams doesn’t saunter, slouch or sit idly during his 16-hour work days. Williams traces his first infatuation with astronomy to a 1952 junior high science class. He turned the pages of a school magazine to a picture of Mars. He, like scientists today, was excited by the possibility of life on the planet.

He returned to school the following day with his magnifying glass and searched the picture for canals or other signs of extraterrestrial life. He was disappointed, but he knew then he wanted to be an astronomer. “It was straight out of William James’s Varieties of Religious Experiences,” Williams says. “I had a religious experience and that is what did it. From that day there was obviously something in me that wanted to do it. I would never have changed it. ” He soon barraged his parents, who were fundamentalist Baptists, with questions about the origins of life and the universe.

They viewed his growing obsession with science in general and astronomy in particular with concern, but they didn’t keep him from attending Berkeley or Wisconsin, where he excelled. “Bob derived the photoionization model of gaseous nebulae,” says Donald Osterbrock, Williams’s doctoral advisor at Wisconsin. “It is still used today. ” Williams left Wisconsin in 1965 with a Ph. D. and immediately was hired as an assistant professor at the University of Arizona. Without having endured the purgatory of post-doctoral training, Williams was on the tenure-track at age 24.

He piled up publications while studying quasars, the universe’s most powerful objects, which emit 100 times more energy than the average galaxy. Arizona awarded Williams tenure before he turned 29. But Williams eventually became bored with quasars, tenure, and teaching undergraduates he considered too grade-conscious. After 18 years at Arizona, Williams did the unthinkable: He abruptly resigned. He didn’t even have a job in sight. His colleagues at Arizona were stunned. “I was astounded,” Osterbrock recalled. “People thought I was nuts,” Williams says.

I remember one professor at the university who said, ‘Bob, what are you doing? I hear talk that you ran off with the baby-sitter! ‘ People thought it was a mid-life crisis, and my marriage was on the rocks — which was hardly the case — Elaine and I have now had our 35th wedding anniversary. ” Unknown to his colleagues at Arizona, Williams had long been influenced by the writings of the late German-American theologian Paul Tillich. “That’s a side of Bob that I don’t know very well,” says Williams’s longtime collaborator, then at Arizona, Weymann.

I was a successful, tenured professor but I just felt I wasn’t living near enough to the edge,” Williams says. “I wanted to put myself in more of a risky environment because I think I somehow need that, and respond to it. I had no job, no expectations, I just wanted to see what was out there. I wanted to throw myself into the maelstrom. ” The maelstrom took the form of a one-year fellowship at NASA and a one-year visiting appointment at the European Southern Observatory, before Williams became director of the Cerro Tololo Inter-American Observatory in La Serena, Chile.

He remained as director of the observatory for eight years. He took over as director of the STScI when the former head and driving force behind the Hubble project, astronomer Riccardo Giacconi, stepped down in 1993. Williams’s office at the STScI reflects his high-energy pace since he took over. His desk and a nearby table hold stacks of technical monographs, publication reprints, and color prints and slides of galaxies, nebulae, planets, and other objects photographed by Hubble. A poster of the 2,500 or more lumpy, oddly shaped Deep Field galaxies is pinned to his office door.

It is the only work-related picture hanging in his office. The image has become a talisman for him and astronomers around the world. They had hoped for a picture of the early universe ever since NASA’s Cosmic Background Explorer satellite discovered tiny ripples — one part in 100,000 — in the microwave background of the universe. The ripples were made roughly one million years after the Big Bang. Did the wrinkles themselves precipitate, roughly 5 billion years later, the galaxies seen in the Deep Field image?

We haven’t yet seen what happened during the intervening time, the time between COBE and that picture,” Williams says, pointing at the Deep Field image, “and we really need to fill in the gap. That’s one of the places where observational astrophysics is going to go in the next several decades. ” Williams says Hubble also will be used to probe the dense and dusty centers of distant galaxies. Because of the galaxies’ great distances from Earth, astronomers have needed a powerful telescope orbiting above Earth’s optically distorting atmosphere to investigate them.

There are really interesting things going on in the centers of galaxies,” he says, seated relaxed and upright in a padded chair in his office. (He rarely, if ever, speaks to visitors or STScI staffers from behind his desk, preferring instead to sit with them around a coffee table. ) The things that interest Williams inside galaxies include black holes, accretion disks of matter swirling in vortices around super-dense objects, and highly energetic jets, or the “exhaust products” that spew from compact objects, which in some cases are black holes.

Williams jumped up from his chair, strode to his desk, and held up a Hubble image. “Look,” he says, holding a color slide toward the late-afternoon sunlight slanting into his office from a south window. The slide showed a colossal puff of hot plasma extending from a recently formed protostar in Ophiuchus. Williams not only encourages astronomers around the world to conduct follow-up studies of such Hubble discoveries, he also makes it easier for them: Hubble’s huge archive of observations can be re-researched, and he made his Deep Field data immediately available via the Internet to anyone who wanted them.

He’s extremely anxious that the STScI have the respect of the scientific community,” says Weymann. “And he really cares about the science. ” Williams deferred his personal observation time in 1994 so that planetary astronomers could record and study the Shoemaker Levy-9 comet-fragment impacts on Jupiter. The giant planet and its moons have subsequently become a favorite Hubble target. Hubble helped NASA pick the December 1995 entry site for the Galileo probe into Jupiter’s atmosphere. No images obtained by an earth-orbiting telescope can compete with those obtained by such space probes.

When Williams isn’t induced to give up his discretionary time, which amounts to 5 percent of Hubble’s schedule, to study unexpected solar system interlopers, he likes to use the time to roll the dice. For example, after the Shoemaker-Levy 9 collision in 1994, he aimed Hubble at the fringes of the galaxy NGC 5128 in Centaurus, where he expected to find prolific star-forming regions. Unfortunately, the dice came up snake eyes. Undaunted, he rolled again in 1995 for the Deep Field observation.

There were no guarantees that the 10-day observation, the longest to date made by the orbiting telescope, would reveal much of anything. But this time, the dice came up a lucky seven. “Bob deserves enormous credit for the Deep Field,” says Holland Ford, an astronomy professor with a joint appointment at the STScI and Johns Hopkins University. “He was willing to take the risk, and the criticism if it failed. ” Williams has begun to earmark time on Hubble for observations judged by the members of Hubble’s telescope allocation committee (TAC) to be “risky.

He often equates the term risky with innovative. He fervently wants astronomers to try observations that haven’t been tried before or ones that can’t guarantee meaningful scientific results. Ironically, Williams, the consummate risk-taking nonconformist who abhors tenure, has become a Pied Piper for astronomers who not only hope to make significant discoveries, but also gain tenure with the help of Hubble. NASA, among the more politically attuned scientific agencies in the federal government, insists that Williams try to make Hubble “user friendly.

And a 1996 NASA/Hubble Space Telescope Project evaluation gave the STScI a perfect 100 percent rating in meeting its objectives. But Williams is taking another risky move: this time a political one that could affect his leadership of STScI. He has quietly begun to nudge the STScI away from its recent tendency of providing Hubble time to most astronomers who request some. The change is financially significant: Whoever gets observing time on Hubble also is eligible to receive a piece of the $20 million a year NASA sets aside for so-called data-reduction grants for the telescope’s users.

That $20 million constitutes almost half of all the salaries paid to U. S. astronomy post-doctoral fellows. The largesse explains why Hubble’s popularity among astronomers is so high and also why the telescope’s photo album has 100,000 snapshots in it. Williams is influencing more than the ebb and flow of money. He maintains that the trend of providing ever smaller observations and diminishing slices of the $20 million pie to many principal investigators may be counterproductive. Williams stopped short of calling his move a scientific version of welfare reform.

But during the first day of my visit to STScI, Williams charged 50 noninstitute astronomers who had volunteered to serve on the Hubble TAC to remember in their deliberations that “the Hubble is not a public works project. ” “Officially, the director makes the Hubble allocation, and strictly speaking you are making recommendations to me,” Williams told the TAC panel members seated in the STScI’s main auditorium. “But I can assure you that it is rare, in fact I cannot think of ever having reversed a TAC recommendation.

However, Williams, not the TAC panels, decided that the TAC’s operating procedures will inevitably take Hubble time away from small observations of a few Hubble orbits and give that block of time to longer observations. During a break in the TAC meeting, Williams returned to his third-floor office, decorated with, among other artifacts, an Andean wool tapestry and a miniature stained glass rendition of the “Blue Virgin” from France’s Chartres cathedral. Williams lunged to a ringing telephone. The caller said the vice president wanted a Deep Field poster as part of a planned speech about the future of American science.

Williams added pleasantries and short sentences before a swift good-bye. Next, he swiveled his chair to a computer keyboard behind him and swiftly rat-tat-tatted an e-mail message, a reply to one of dozens waiting to be read. Later that day, one of the messages was from an indignant colleague who was upset that, in his judgment, Williams had equated “small” with “public works. ” Miffed at himself for not explaining his move and its intended effect to get more interesting science out of Hubble, Williams grumbled, “Oh! That’s not what I meant!

By the beginning of the next century, Williams says 40 percent of Hubble’s time will be devoted to medium-sized projects of two to six days, and a quarter of Hubble’s schedule could be devoted to about nine large projects, each taking 10 days to two weeks or even longer, per year. Williams concedes that his move may lower the batting average of those applying for Hubble time, but he says the policy also should generate more scientific home runs, “and maximize discovery-space. ” Opposition has been restrained, so far.

But a critic says Williams’s idea will give home-field advantage to the astronomers who are affiliated with big, prestigious ground-based telescopes. “Caltech has the Keck Telescope and they can use it for leverage to get time on the Hubble Space Telescope, thereby concentrating yet more power in the hands of a small number of people,” says MIT astronomer Paul Schechter. He says the batting average of all astronomers who have sought National Science Foundation grants already has declined as that federal agency has shifted to larger, but fewer, grant awards.

The NSF has for the last three years not funded my work because of the shift,” says Schechter, one of the nation’s leading cosmologists. “I haven’t got a graduate student. ” Caltech astronomers took one look at the Deep Field data on the Internet and pointed the 10-meter Keck Telescope in Hawaii at Williams’s new galaxies. Keck’s spectrographs were used to measure the Doppler-shift of light from several of the galaxies to longer, redder wavelengths. Other telescope spectrographs also have measured the so-called redshifts of individual Deep Field galaxies.

The results have been stunning: Light left some of the galaxies when the approximately 12-billion-year-old universe was a few billion years old. Cosmologists who had used mathematical models to try to explain how galaxies coalesced from gas now had real data. In just one of what almost certainly will be many groundbreaking follow-up discoveries, astronomers using the Infrared Space Observatory (ISO) recently reported that some of the youngest galaxies in the Deep Field had immense star-formation rates; 10 to 1,000 solar masses per year — compared to the current star-forming rate in our Milky Way Galaxy of just one solar mass per year.

The ISO observation and the Deep Field image have possibly caught the first brilliant star-forming flashes of what we call the early universe — a brief period when the elements essential for life, carbon, nitrogen, oxygen, iron, and others, were first being minted. “The attention has shifted: It’s been a sea change to study these very high redshift galaxies. ” says MIT’s Schechter. “We didn’t know what was out there, and now people are trying to follow up on the Deep Field image and work on it. ” When asked to discuss the Deep Field observation, Williams’s professorial voice thickens and slows like aged Maryland honey.

I’m going to do it again just because . . . Um . . . I think it has turned out to be . . . an important observation. Ah . . . and to confirm that the first Deep Field was not atypical, for drawing implications of the large-scale structure of the universe: You want to make sure the conclusions are based on a field that is typical and not abnormal in some way. ” Look for a southern version of the Deep Field image, he says, in late 1997. Despite the satisfaction he feels about the Deep Field image, he says astronomers have much to learn about galaxies closer to home.

He and others were taken aback with the beautiful 1995 Hubble image of embryonic stars bubbling from the tips of vast “elephant trunks” of dust and hydrogen gas protruding from the Eagle Nebula. The nebula, also called M16, is a nearby star-forming region 7,000 light-years away in the constellation Serpens. The elephantine gas clouds are dense enough to collapse under their own weight to form stars of various sizes. The clarity of the Hubble pictures gave the elephant trunks a three-dimensional look.

Young, hot stars forming on the periphery of the hydrogen clouds added to the 3-D effect as they boiled the gas away in an effervescent process called photoevaporation. Unfortunately, time is not an ally of Hubble. The bombardment of cosmic rays and other radiation is expected to take its toll on the 2. 5-ton telescope: Its expected lifetime will expire in 2005. The telescope’s mortality was apparent during my visit: The telescope had shut itself down the day before we arrived after its software discovered a glitch. A detector indicated that one of its four reaction wheels, or flywheels, was not spinning at the right speed.

The momentum of the four reaction wheels keeps the telescope pointed in the precise directions called for in each of thousands of observations made each year. The software adjusts the rotational speed of each reaction wheel to twirl and stop the school bus-sized telescope at its next target. As the TAC panel pored over proposals, scientists and engineers with STScI and NASA intently tried to figure out what had gone wrong. The problem was traced to a capacitor, a device that stores electrical energy. The capacitor was fixed, and the Hubble was back on duty in a few days.

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