UW astronomers ride a wave of discovery

Fifty years is no time at all for a universe that dates back 13.8 billion. But for those who study the sky, the past five decades have changed everything.

When the university of washington’s astronomy department was established fifty years ago, the only known planets were in our solar system. Now, nearly two thousand planets have been identified in more than a thousand solar systems, and we have tools to predict which ones might sustain life. Scientists can measure the temperature, density, and chemical composition of celestial objects with stunning accuracy. Telescopes can see farther than ever, reaching galaxies formed shortly after the Big Bang. And the UW has been at the forefront of many of these astonishing advancements.

“With technological advances, opportunities have just exploded in astronomy,” says Bruce Balick, professor emeritus of astronomy, “and we’ve caught each wave as quickly as we can.”

Astronomers face a unique challenge. Because they study objects that may be millions of light-years away, most of their information comes from analyzing the light that reaches Earth. To collect that light, they use instruments with massive mirrors—the larger, the better—and sophisticated electronic detectors that turn the light into signals. Not exactly your build-it-yourself backyard telescope. And nothing like the refracting telescope at the historic Theodor Jacobsen Observatory on the UW campus.

The observatory is almost as old as the University. The telescope there was purchased in 1891 with $3,000 in state funds, and the building that houses it was built four years later with leftover sandstone from the construction of Denny Hall. The observatory was later named in honor of professor Theodor Jacobsen, the sole astronomy professor at the University for nearly 40 years—until 1965, when the University added four new positions to create the Department of Astronomy in the College of Arts and Sciences.

Professors George Wallerstein and Paul Hodge were the first to be hired. Before they’d unpacked their bags, they started planning for a new observatory. Wallerstein, the department’s first chair, visited half a dozen sites east of the Cascades, and—after considering weather patterns, light pollution, accessibility, and other factors—chose a remote site near Ellensburg. The Manastash Ridge Observatory opened in 1972, with a 30-inch telescope that is still used by undergraduate majors today.

Even as the observatory was being built, Wallerstein knew it was more suitable for student projects than faculty research. Only a few universities had viable research telescopes due to the prohibitive cost. Most scientists applied for time on the large national telescopes, with demand far exceeding the resources. The situation was particularly challenging for graduate students, forced to compete with more seasoned astronomers.

Determined to change the situation, UW’s astronomy faculty began thinking big. After several false starts, in the 1980s they were able to pool resources with four other schools including the University of Chicago and Princeton University to build the Apache Point Observatory in New Mexico. Its impressive 3.5-meter mirror guaranteed the UW a hefty chunk of observation time. “With access to that telescope, our ability to recruit new faculty and students just soared and our national reputation took a huge leap forward,” says Balick. “It gave us a national presence.”

The more we find out, the more new questions emerge.

Bruce Balick, professor emeritus of astronomy

Apache Point has been a mainstay of the UW astronomy program, but faculty have also had a hand in many other major national projects in astrophysics. They have participated on teams to develop instruments for the Hubble Space Telescope and similar telescopes in orbit. They led NASA’s Stardust, the first U.S. mission to collect dust from a passing comet. They have advised on the development of powerful supercomputers used by theoretical astrophysicists. They helped found the UW Astrobiology Program, which studies the Earth’s past environments and looks for possibilities of life within our solar system and beyond. And they have been leaders in survey astronomy, which uses specialized equipment to map the sky.

The UW got into survey astronomy early as a participant of the Sloan Digital Sky Survey (SDSS), completed in 2000. While other telescopes aim to capture faint light from the earliest galaxies, wide-angle telescopes like the SDSS’s study the sky to map cosmic patterns and identify changes over time. Data collected by SDSS is open source, available to anyone with a computer—including UW undergraduates, who have identified a thousand new asteroids.

Scott Anderson, chair of the astronomy department, insists it’s not hyperbole to describe SDSS as among the most successful projects in the history of the field. “That’s true by all kinds of independent measures,” he says, “including how many Ph.D.s it has produced, how many publications it has produced, how many people are engaged in citizen science.” Many SDSS discoveries—from the chemical composition of thousands of stars to patterns in the distribution of galaxies—provide clues to the history and fate of the universe.

Given the success of SDSS, it’s no surprise that the next generation of survey telescope is in the works—and that UW astronomers are involved in all aspects of planning and design. The Large Synoptic Survey Telescope (LSST) will be an 8-meter instrument featuring a digital camera about the size of a Volkswagen Beetle. The camera, based in Chile, will take three pictures every minute, completing a survey of the visible sky every three nights and producing an almost unimaginable trove of data. As with most major astronomy initiatives, much of the funding comes from the National Science Foundation.

“The LSST is one of the most exciting experiments in astrophysics today,” says Andrew Connolly, professor of astronomy. “When it comes online at the end of this decade, it could completely transform our knowledge of our universe, from understanding how dark energy drives the expansion of the universe to identifying asteroids that may one day impact the Earth.”

No doubt any new discoveries will lead to many more questions—which is, after all, the fun of research.

“Fifty years ago, I would have thought, ‘We’re going to understand all of this someday,’” says Balick. “However, the more we find out, the more new questions emerge, which is humbling. The future will certainly bring us many wonderful surprises no matter how it plays out.”