Key Takeaways:
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Bob Williams took a big risk with his “Hubble Deep Field” project, but it led to a groundbreaking discovery of countless galaxies.
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What appeared to be empty space was actually teeming with galaxies, far more than previously thought.
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The deep field observations showed that young galaxies were more irregular and chaotic than their older counterparts.
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Coordinating with ground-based telescopes helped astronomers measure distances to the observed galaxies.
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The project revolutionized our understanding of the universe’s vastness and the abundance of galaxies.
In 1995, astronomer Bob Williams wanted to point the Hubble Space Telescope at a patch of sky filled with absolutely nothing remarkable. for one hundred hours.
His colleagues told him it was a bad idea and a waste of precious telescope time. It was said that people would kill for that long with the sharpest tool in the shed, and that in addition, Williams’ desired distant galaxies would never be bright enough for Hubble to detect.
But Williams was undeterred. Furthermore, it didn’t really matter how much his colleagues protested, to be honest. He was able to use some of Hubble’s time personally because he was the director of the Space Telescope Science Institute. He says, “Such a long, risky project would never have been approved by the telescope allocation committee.” “But I could do anything I wanted because I had 10% of the telescope time as director.”
Wiliams believed that the billion light-year stare could reveal some of the faintest and farthest galaxies ever seen and capture eons of galactic evolution in a single frame. And for him, the experiment made perfect sense, consequences be damned, because the possible observations were so crucial and fundamental to comprehending how the universe evolved.
“Scientific discovery requires risk,” Williams says. “And I was at a point in my career where I said, “If it’s that bad, I’ll resign. I’ll trip over my sword.
So, with his job perhaps on the line, Williams went off, put together a small team of post-docs, and did exactly as he’d planned. For 100 hours, between Dec. 18 and 28, Hubble stared at a patch of sky near the Big Dipper’s handle that was only about 1/30th as wide as the full moon. The telescope imaged the area for a total of 342 times, exposing each image for 25 to 45 minutes. After the photos were combined, processed, and colored, they were made public 17 days later.
As it happened, “nothing” was actually stuffed with galaxies. Over 3,000 of them erupted, with an estimated age of 12 billion years. The red, white, blue, and yellow smudges of light that jumped out of the final composite image were spiral, elliptical, irregular, and cracked the universe in ways that scientists could never have predicted.
According to John Noble Wilford of The New York Times, “With this achievement, the estimated number of galaxies in the universe had multiplied enormously — to 50 billion, five times more than previously expected.” Furthermore, the appearance of some of the older galaxies—those far-off, dim ones that Hubble was actually unable to observe—was noticeably different.
According to Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics, “the galaxies were very irregular when they were young— they were having collisions, they were erupting, they were having adolescent outbursts.” He was one of the scientists who first opposed the deep field concept. “I was wrong, Bob was right.” The way that discretionary time was used was brave, he claims.
However, there was more. Prior to the event, Williams had made contact with astronomers at the Keck telescopes in Hawaii, asking them to aim their guns from Earth toward the same area of the sky. Collectively, the observations enabled astronomers to uncover enormous areas of the cosmos by creating a sort of practical for calculating cosmological distances to these galaxies.
As for public relations? The picture that is currently referred to as the Hubble Deep Field fascinated almost everyone. Claiming it was a victory would be a vast understatement. “The nerve that it took to say, ‘We’re going to point where there isn’t anything,’ was interesting,” says John Mather, a Nobel Laureate and senior project scientist for the James Webb Space Telescope. “And Bob Williams got a lot of nice recognition for that leadership.”
Williams’ experiment was soon duplicated in a new area of the southern constellation Tucana, and the resulting patch of sky became known as the Hubble Deep Field South. A mere million seconds of nothingness exposed the Hubble Ultra Deep Field, containing an even greater number of galaxies than before. And in 2012, the Hubble eXtreme Deep Field was created by combining ten years of Ultra Deep Field exposures.
According to Hubble senior scientist Jennifer Wiseman of NASA’s Goddard Space Flight Center, these photos have provided “a glimpse of the hundreds of billions of galaxies that fill the universe.” “That gives me and many people pause to be quiet and contemplate this majestic universe we live in, and be grateful we have a chance to look at it.”
Project scientist Jason Kalirai, working on the Webb telescope, goes one step further and puts the Hubble Deep Field within an impressive historical structure. “‘What is our place in the universe?’ is a question that even the earliest civilizations probably asked themselves.” There have been a few times in our history when the prevailing answer to that question has been overthrown, he says. Two examples of this are when Galileo used his telescope to study Jupiter and its moons and contributed to the discovery that not everything in the universe revolves around the Earth and when astronomer Edwin Hubble demonstrated in the early 1900s that not all light in the sky originates from within our own galaxy.
The Hubble Deep Field is a third. “It showed that the universe is teeming with these galaxies, and if you do a census of how many galaxies you see, and think about how many more are in the night sky, you can conclude that there are as many galaxies as there are stars in the Milky Way,” Kalirai says.
What about Williams? In a typically understated manner, he summarizes the experience thus far: “It turned out to be a neat image.” Actually.
