Baltimore, Maryland — In the summer of 1995, Robert Williams, then the director of the Space Telescope Science Institute, faced a significant dilemma regarding the future of the Hubble Space Telescope. Renowned astronomer John Bahcall, one of the telescope’s original advocates, made an unusual plea. He urged Williams to avoid directing Hubble towards a seemingly empty expanse of space to search for distant, unknown galaxies. The proposed mission, aimed at creating an unprecedented “deep field” view of the universe, was fraught with risk. Although Bahcall acknowledged Hubble’s potential for astronomical discovery, he doubted its ability to uncover new galaxies — a lingering concern since the telescope’s troublesome debut in 1990, when a flawed mirror resulted in blurry images and significant public ridicule.
Despite the uncertainty, Williams felt compelled to proceed. “I told him that I’m willing to fall on my sword,” he recalled in a recent interview, reflecting on the challenges that Hubble faced.
Not long after that pivotal conversation, Williams made the bold decision to aim Hubble at a blank sector of sky for ten consecutive days. The results were groundbreaking. The images transmitted back to Earth revealed a “cosmic zoo” of approximately 3,000 galaxies, illuminating a vast expanse that had only been theorized before. Jennifer Wiseman, who was a postdoctoral researcher at the time and is now Hubble’s senior project scientist, described the moment as “mind-blowing.” Each of those distant points of light represented billions of stars and planetary systems, transforming our understanding of the universe.
The ambition to capture such a deep field of view traces its origins back to the late 1960s. In 1969, a National Academy of Sciences report proposed the concept of a large space telescope. By the mid-1970s, funding was secured, and the project formally began in 1978. The telescope, named in honor of astronomer Edwin Hubble, was launched in 1990. However, the aftermath of the launch brought disappointment. Bahcall himself had published a paper stating the fresh reality of Hubble’s limitations: the expectation was that it would not reveal any new types of galaxies. That assertion left many, including Ray Villard, the telescope’s media chief, anxious about its future.
Adding to the existing concerns, Hubble’s initial mode of operation proved to be costly. After a malfunctioning mirror necessitated a Space Shuttle servicing mission — one that cost over $1 billion — Hubble’s reputation was severely damaged. Political circles criticized NASA, and public confidence in the mission was low. Despite the daunting odds, Williams believed in taking risks for the sake of discovery. “If you want to make discoveries, one must take risks,” he stated.
The selection of the deep field target sparked its own controversy. Many on Hubble’s advisory committee disagreed with Williams’ choice to aim for an unremarkable section of sky, fearing it would yield nothing. Still, Williams used his authority as director to bypass standard protocols and secured time for the observation. The payoff was extraordinary, as Hubble unveiled thousands of galaxies in what was previously dismissed as empty space.
Three decades later, the impact of the Hubble Deep Field continues to resonate. It not only expanded our understanding of the cosmos but also paved the way for future telescopes. Hubble has contributed to groundbreaking research, including insights into black holes, cosmic expansion, and the atmospheres of distant exoplanets. Wiseman noted that Hubble currently enjoys a period of unparalleled scientific productivity, as the number of research papers derived from Hubble data reaches a historic peak.
Hubble’s legacy extends beyond its immediate findings as it inspired the next generation of observatories like the James Webb Space Telescope. This new technology aims to peer even deeper into the universe, building upon the foundation laid by Hubble. “Hubble baked the cake,” Villard commented, likening Hubble’s contributions to an essential starting point for future exploration.
Looking back, Williams reflects on the profound lessons that the Hubble Deep Field offers. Gazing into those ancient galaxies is akin to exploring our origins, revealing threads that connect humanity to the universe’s beginnings. “We’re looking at our origins,” he concluded, emphasizing the telescope’s role in bridging the gap between our past and present in the cosmos.