Who was Vera Rubin? Here's what to know about the astronomer behind dark matter.
Vera Rubin had just finished her ice cream when she saw something that would change astronomy forever. It was long past midnight one early morning in the 1960s, and Rubin and her colleague Kent Ford were at Kitt Peak National Observatory in the middle of the Arizona desert. That night they were tracking how hot gas from young stars circled Andromeda, the Milky Way's galactic neighbor. Rubin and Ford would trade off recording the gases' chemical fingerprints or processing photographic plates. While waiting for the plates to develop, Rubin would eat an ice cream cone.
Four cones in, Rubin could draw Andromeda's rotation curve—she could plot the distance of gas clouds on an X-axis and their speeds on the Y-axis. At the time, astronomers assumed the stars circling a galaxy would act like the planets circling the sun in our solar system. Stars closer to the galaxy's center would circle quickly, while stars farther out would orbit slowly because core's gravitational pull was weaker out there. The curve, then, should start high and fall the farther the distance from a galaxy's center, astronomers assumed.
Rubin never liked assumptions. She'd rather collect data, even if it met expectations. But what Rubin saw in that rotation curve didn't. The close-in and far-out stars seemed to be circling Andromeda at roughly the same speeds. The curve was flat.
The ice-cream fueled find, and those that followed, forced astronomers to rethink not only what we know about galaxies but also what we know about the universe. It forced them to reimagine the fabric of the cosmos. They'd ultimately conclude that that fabric included a mysterious substance, an invisible form of matter now known as dark matter, that to this day we don't fully understand.
But it wasn't just this Copernican-esque discovery of flat rotation curves that made Rubin a legend. It was the way she discovered it, the way she advocated for equality in astronomy, the way she welcomed new astronomers into the field without hesitation and kept going to the telescope well into her eighties, which is when I got to know her.
It was November 2007 when I joined Rubin at Kitt Peak. No photographic plates. No winter ice cream. Just a veteran astronomer, a cub reporter, and a spiral galaxy to observe. It was in her reminiscing during those nights that I came to understand that her dark matter discovery story wasn't one of a cliché lone genius and a eureka moment. Her observations were a fold in the braid that led to dark matter becoming astronomy dogma. And, her decades of discoveries were only part of her legacy, with her outspokenness and moral compass cementing it to memory. It's this layered legacy I see in the new Vera Rubin Observatory, which will deliver its first images this month.
(A century ago, this pioneering astronomer discovered what stars are made of.)
Eleven-year-old Vera Rubin—Vera Cooper, then—stared at an imaginary line running down the bed she shared with her sister, Ruth, then rolled over, defeated. She was the younger of the two and was told she couldn't sleep next to the small row of windows that lined the inner wall of the bedroom and fortuitously faced north in their rented townhouse in Washington, D.C. But even from the inside edge, the starlight caught Vera's attention; she was mesmerized. Every night, she'd crawl over her sister Ruth to get a better view of the sky. 'There was just nothing as interesting in my life,' Rubin once said, 'as watching the stars.'
Through her childhood in the 1930s, she would hang out by the window tracing star trails, check out library books about scientists, and build her first telescope with her dad, who worked for the Department of Agriculture. He'd also take her to the local amateur astronomy club where she heard talks by astronomers like Harlow Shapley, then the director of the Harvard Observatory.
By the time Vera was in high school, she sought out cosmology books like James Jean's The Universe Around Us and Arthur Eddington's The Internal Constitution of Stars. At Vassar College, she majored in astronomy, taught herself how to observe using the college's telescopes, and took summer positions at the Naval Research Laboratory to gain experience doing science experiments. Around then, her parents introduced her to Robert Rubin. They began dating and were married in August of 1948—what many assumed was the end to Rubin's astronomy career.
Vera had gotten accepted to Harvard for her master's degree. But she chose to go to Cornell University, where Bob was working on his Ph.D. in physical chemistry, instead. There were roadblocks, but Rubin found mentors in physicist Richard Feynman and astronomer Martha Star Carpenter, and her husband, who helped her launch a research project see if the universe rotated—all while they started a family. When she presented her results at the 1950 American Astronomical Society meeting in Ithaca, New York, the press was sensational. 'A young mother startled the American Astronomical Society,' the Associated Press reporter wrote. Her work challenged convention, and she would again while working on her Ph.D. at Georgetown University.
Despite her research, Rubin often felt like an imposter. She earned her Ph.D. in 1954, and about a year later, took a faculty position at Georgetown. She and Bob were growing their family then, and for the next few years, she took on a variety of research projects, always analyzing others' data. Even then an imposter in her own mind, she'd advocate for her students, threatening to pull a paper from publication because the journal wouldn't print the names of the students who worked on it, for example. But, after nearly a decade, Rubin grew tired of relying on others' work to do her own.
Finally, she got a break. Observational astronomers Margaret and Geoffrey Burbidge, famous for their paper on the origin of chemical elements in the life and death of stars, invited Rubin to work with them. They were also interested in galaxies and taught her the technique to calculate stars' and gas clouds' speeds. A first taste of being a real astronomer, she said. Shortly after, Rubin knew she needed access to a telescope. She went to the Department of Terrestrial Magnetism, part of the Carnegie Science Institution and talked with radio astronomers there. Then, she asked for a job. She moved into Kent Ford's office on April Fool's Day in 1965 and never left.
A few years later, she and Ford discovered Andromeda's flat rotation curve. Then flat curves in other galaxies. By the early seventies, Princeton theorists Jeremiah Ostriker and Jim Peebles were running computer simulations of galaxies to figure how to get the galaxies to stay together in dizzying spirals like Andromeda. Only when the duo enveloped particles representing galaxies in spherical halos in their simulations would the galaxies cease to fly apart. They needed some extra mass to hold them together.
Observations and simulations combined, astronomers knew they needed to rethink how the universe worked, and slowly the idea of dark matter took hold. By the early 1980s, consensus emerged: Dark matter existed, most conceded.
(How will the universe end? The answer might surprise you.)
While this shift was happening, Rubin was pushing for another—equality in astronomy. She worked on an American Astronomical Society report that highlighted issues such as discrimination in hiring, both "blatant or not", a pay gap between men and women with the same qualifications, and lower pay for married women. And, of course, she placed a cutout of a woman on the door of the historic men's-only bathroom at Palomar Observatory in California.
Younger astronomers looked up to Rubin, appreciating her candor on sexism and having it all—career, family, and a loving relationship. 'For many of us, Vera had a personal impact. She demonstrated that a woman who was as cheerful, warm, generous, and down-to-earth as she was could be a successful astronomer,' astronomer Deirdre Hunter wrote not long after Rubin's death in 2016. She fostered a sense of belonging, one I felt too.
It's how I, at 22, found myself at Kitt Peak with Rubin, on her final time observing, absorbing her life lessons on her grace, wit and grit. She was humble and a deep thinker. Many say she deserved a Nobel Prize. She questioned if she wanted it. 'It changed your life,' she said, and 'not always in a good way.' While studying her galaxy, I sensed of battle of wills, the tug of homelife and professional life. Her husband was ill and her childhood wonder of the universe unfulfilled.
Rubin's wonder lives on in the observatory that will bear her name. It will challenge our assumptions just as she did, and I hope it will remind us that her legacy is more than a telescope. It is a blueprint for humanity—to be curious, never assume, and above all be kind.
This essay is adapted from the author's book Bright Galaxies, Dark Matter, and Beyond: The Life of Astronomer Vera Rubin.
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Yahoo
16 hours ago
- Yahoo
Satellite streaks: Can the huge new Vera Rubin Observatory function in the megaconstellation age?
When you buy through links on our articles, Future and its syndication partners may earn a commission. When astronomers first dreamt up the Vera Rubin Observatory in the 1990s, the sky above the Chilean Cerro Pachón, where the star-observing machine was to be located, looked different than it does today. Dotted with millions of stars, galaxies and nebulas, it was only occasionally crossed by a lone satellite. Then, just a few years before the observatory's expected inauguration, the era of megaconstellations took off, and astronomers found themselves racing to find ways to protect the telescope's images from satellite contamination. They didn't have much time. When construction of the $680 million observatory began in 2015, everything was still going according to plan. Four years later, SpaceX launched the first batch of Starlink internet satellites, Starlink trains became a thing, and astronomers realized that the satellites, orbiting only 340 miles (550 kilometers) above Earth, were too bright not to interfere with their observations. Vera Rubin, due to its wide field of view and exceptional sensitivity, was to feel their presence especially keenly. "All of the characteristics that make Vera Rubin Observatory so amazing for surveying the whole southern sky also mean it's going to see a whole bunch of these satellites," Meredith Rawls, a research scientist for the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) and an astronomer at the University of Washington, told The Vera Rubin telescope, which is set to open its eyes to the sky later this month, has a 26-foot-wide (8.4 meters) mirror, one of the largest in the world. It's also fitted with the largest camera ever built for an astronomical telescope — a 5.4-foot-wide (1.65 m), 3,200-megapixel device with 189 CCD detectors. The telescope will be able to tilt its mirror to change its view of the sky every night in order to complete a whole sky survey every three days. In each sweep of the celestial dome, the telescope will not only capture the myriads of stars and distant galaxies invisible to the human eye, but also the thousands of satellites that are millions of times brighter than those precious astronomical targets. And this problem will only get worse with time. SpaceX was initially talking about a constellation of 12,000 satellites but now plans a fleet of 42,000 spacecraft. Other broadband operations — like Amazon's Kuiper network and the Chinese projects Guowang, Qianfan, and Geespace — intend to launch tens of thousands of satellites of their own. Currently, about 10,000 satellites orbit Earth, but the number could increase to 100,000 in the next decade if all those plans come to fruition. "It's unfortunate that this huge increase [in the number of satellites] is coinciding with the decade of Vera Rubin's operation," said Rawls. "It's existentially frustrating that we are putting a bunch of stuff in orbit that is interfering with our views of the cosmos." Rawls has worked on the Vera Rubin Observatory project since 2016, initially developing image processing algorithms to filter out faults of the camera's sensors and detecting unexpected celestial phenomena such as supernova explosions. The arrival of Starlink and its counterparts forced her to refocus. Today, she develops techniques to flag the presence of satellites in images and distinguish them from objects of astronomical interest, including passing asteroids. Still, Rawls said that the satellite streak problem is not a death threat for Vera Rubin's science mission. She describes the satellite streaks more like "bugs on a windshield" on a summer night, obscuring the view at times, but not completely ruining it. "It's true that a large fraction of exposures is going to contain a satellite streak, but the field of view is big, and so the number of actual pixels that are affected is very small," said Rawls. "At most, [the satellite streaks] are a few hundred pixels wide. But a single detector has 4,000 pixels, and the camera has 189 CCD detectors tracking the sky." Noelia Noël, a professor of astrophysics at the University of Surrey in the U.K., told that up to 40% of the images captured by the Vera Rubin telescope over its 10-year mission are expected to have streaks in them. "If you take 10 million images, over 4 million of them could be degraded," said Noël, who is also part of Vera Rubin's LSST project. "This is a huge waste of taxpayers' money. One night of Vera Rubin's observations costs something like £60,000 [about $81,000]. So, if you ruin the images, it's your money going to waste." Apart from outshining legitimate objects of interest, the satellites could also be mistaken for real celestial phenomena. In 2021, for example, a group of scientists thought that a star exploded in the oldest known galaxy when they observed a sudden brightening in images taken by the Keck Telescope in Hawaii. It later turned out that, as the astronomers pointed their instrument at the galaxy, a piece of debris passed in front of their field of few, reflecting sunlight. "We don't want to give people a catalog of data where each pixel is supposed to be an actual star, and then surprise, a third of them are just bright detections where it happened to be in the satellite trail," said Rawls. The algorithms developed by Rawls and her colleagues will use a stacking method to compare multiple images of the same portion of the sky to spot outliers and flag them. If a bright object appears in one image and disappears in the next, it's more likely a passing satellite than a stellar explosion or dimming, said Rawls. Megaconstellations like Starlink are only one part of the problem. In 2022, the American company AST SpaceMobile began deploying a constellation of its BlueBird satellites — essentially giant antenna arrays, each one covering 693 square feet (64 square meters). The satellites are intended to provide 5G via satellite directly to smartphone users on Earth, but they are also insanely bright. They are so bright, in fact, that the Vera Rubin Telescope must plan for their passes in advance in order to avoid them, according to Rawls. "It would be a waste of 30 seconds looking at that portion of the sky with that super bright thing going through," said Rawls. "Thankfully, there are not that many of these super big, super bright satellites yet. But I worry that might change in the coming years." How much of Vera Rubin's precious sky views will be obscured by passing satellites and how much science will be lost as a result remains to be seen. Rawls hopes that attempts to darken satellites, already trialled by SpaceX with limited effects, will eventually succeed, reducing the light contamination to a minimum. Related Stories: — How Earth's new Rubin Observatory will usher in the next era of asteroid space missions — Blinded by the light: How bad are satellite megaconstellations for astronomy? — Megaconstellations could destroy astronomy, and there's no easy fix The International Astronomical Union (IAU) has previously called on satellite makers to strive to make their satellites invisible to the naked eye — an equivalent of magnitude 7 on the scale used to measure the brightness of celestial objects. The magnitude scale is inverse to the actual brightness and logarithmic, meaning that each subsequent grade is 2.5 times dimmer than the previous one. So far, Starlink satellites score between magnitudes 3 and 5. "If satellite operators were able to keep their hardware within approximately the IAU brightness limit, then the impact on ground-based astronomy would be minimal," said Rawls. "In practice, that's not happening, because it's really hard to make stuff that dark." Some glimpses of hope may be appearing on the horizon, however. U.K.-based company Surrey NanoSystems has recently introduced a new type of space paint that is easy to apply, resistant against the harsh space environment and reflects so little light that it could reach the needed brightness reduction. It may be ready just in time.
Scientific American
7 days ago
- Scientific American
This Revolutionary New Telescope Will Observe the Whole Sky Every Three Days
Astrophysics is, as many astrophysicists will tell you, the story of everything. The nature and evolution of stars, galaxies, galaxy clusters, dark matter and dark energy—and our attempts to understand these things—allow us to pose the ultimate questions and reach for the ultimate answers. But the practitioners of these arts, as the late astronomer Vera Rubin wrote in her autobiography's preface, 'too seldom stress the enormity of our ignorance.' 'No one promised that we would live in the era that would unravel the mysteries of the cosmos,' Rubin wrote. And yet a new observatory named for her, opening its eyes soon, will get us closer than ever before to unraveling some of them. This will be possible because the Vera C. Rubin Observatory will do something revolutionary, rare and relatively old-fashioned: it will just look out at the universe and see what there is to see. Perched on a mountaintop in the Chilean Andes, the telescope is fully assembled and operating, although scientists are not able to use it just yet. A few weeks of testing remain to ensure that its camera—the largest in astronomical history, with a more than 1.5-meter lens—is working as it should. Engineers are monitoring how Earth's gravity causes the telescope's three huge glass mirrors to sag and how this slight slumping will affect the collection and measurement of individual photons, including those that have traveled for billions of light-years to reach us. They are also monitoring how the 350-metric-ton telescope will rapidly pan across seven full moons' worth of sky, stabilize and go completely still, and take two 15-second exposures before doing it all over again all night long. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. In this fashion, the scope plans to canvas the entire sky visible from Earth's Southern Hemisphere every three nights, remaking an all-sky map over and over again and noticing how it changes. And computer scientists are finalizing plans for how to sift through 20 terabytes of data every night, which is 350 times more than the data collected by the vaunted James Webb Space Telescope each day. Others are making sure interesting objects or sudden cosmic surprises aren't missed among Rubin Observatory's constant stream of images. Software will search for differences between each map and send out an alert about each one; there could be as many as 10 million alerts a night about potential new objects or changes in the maps. From finding Earth-grazing asteroids and tiny failed stars called brown dwarfs to studying the strangely smooth rotation of entire galaxies sculpted by dark matter, the Rubin Observatory's mission will encompass the entire spectrum of visible-light astronomy. The telescope will continue mapping the sky for 10 years. It may be better poised to answer astrophysicists' deepest questions than any observatory built to date. 'The potential for discovery is immense,' said Christian Aganze, a galactic archaeologist at Stanford University, who will use the observatory's data to study the history of the Milky Way. Put more specifically, Rubin Observatory will collect more data in its first year than has been collected from all telescopes in the combined history of humanity. It will double the amount of information available to astronomy—and to anyone trying to understand our place in the universe. The Rubin Observatory's Mission The observatory's goal was not always so broad. Originally named the Large Synoptic Survey Telescope (LSST), the Rubin Observatory was initially proposed as a dark-matter hunter. Vera Rubin found the first hard evidence for what we now call dark matter, a gargantuan amount of invisible material that shapes the universe and the way galaxies move through it. She and her colleague, the late astronomer Kent Ford, were studying the dynamics of galaxies when they made the discovery in the 1970s. In a spiral galaxy like our Milky Way, the galactic core contains more stars and hence gravity than the outer arms do. This should mean that the objects closer to the core spin around faster than the objects on the outskirts. By observing how stars move around and how their light appears shifted as a result, Rubin and Ford found that the stars on the outskirts were moving just as fast as the ones closer in. They found the phenomenon held across the dozens of galaxies they studied. This pattern defied explanation, unless there was some extra unseen material out there in the far reaches, causing the galaxy to rotate faster on what only appear to be the outer edges. Such dark materials had been proposed in the 1930s, but Rubin's findings showed the power they exerted over regular, visible matter and provided the first evidence that they existed. 'What you see in a spiral galaxy is not what you get,' Rubin once wrote. To date, no one has directly seen dark matter or come to understand its physical nature, including the particles that comprise it in the same way we know the electrons, protons and neutrons that make up regular matter, including galaxies, giraffes and us. Early plans for the LSST sought to shed light on dark matter by mapping its distribution throughout the universe via its gravitational effects. Astronomers also wanted to study how the cosmos is expanding through the work of an equally mysterious companion force called dark energy. But as design on the telescope systems began, astronomers quickly realized the LSST could do much more than study dark matter—it could study almost anything, seen or unseen. 'It is not a telescope that you will be sending proposals saying, 'I want to look over here.' The purpose is the survey,' says Guillem Megias Homar, a doctoral student at Stanford University and member of the telescope team. Mirrors and Cameras The open-ended surveying mission is a boon for astronomers, but it comes with intense design challenges. The telescope has to move across a swath of sky in just a few seconds and stop jittering almost immediately so that its images are clear. At other observatories, where astronomers choose targets ahead of time and plan what they're looking for, telescope engineers have maybe 10 minutes to stop the glass from wobbling in between taking images. Rubin Observatory gets five seconds, says Sandrine Thomas of the U.S. National Science Foundation National Optical-Infrared Astronomy Research Laboratory (NOIRLab), a deputy director of the observatory's construction. 'When you want to move that amount of mass very quickly and be stable, you can't have a very long telescope; otherwise the top wobbles,' she says. 'The light cannot go a long way before it loses focus, and that creates a lot of challenges.' To make the system more compact, Rubin Observatory's main telescope has a unique three-mirror structure. The primary and tertiary mirrors were fabricated to share the same piece of glass. Light bounces off the ring-shaped primary mirror and shines upward into a separate, secondary mirror, itself the largest convex mirror ever made. The secondary mirror again bounces the light back toward the tertiary mirror, which is inside the primary mirror's outer ring. The third mirror reflects light into the camera's sensitive detectors. The primary mirror and tertiary mirror combined give the telescope a collecting area of 6.67 meters. The secondary mirror has a 1.8-meter hole in the middle that the camera and its electronics fit into. And the tertiary mirror has a hole, too, for equipment designed to align the telescope and stop it from wobbling. The camera is a 10-meter-by-10-meter steel cube, small and compact. Margaux Lopez, a mechanical engineer, started working for the SLAC National Accelerator Laboratory after graduating from the California Institute of Technology in 2015 and has been working on the camera ever since. 'The point of this project is to collect a wild amount of data,' she says. 'How we actually do that is to see more of the sky at once, take more images at night and get more detail in each photo—that's the trifecta.' Astronomers often use the full moon's disk to describe a telescope's field of view; for an optical telescope, Rubin Observatory's view is unparalleled. The Hubble Space Telescope observes about one percent of a full moon, and JWST observes about 75 percent of the moon's disk. Each Rubin Observatory image captures an area about 45 times the size of the full moon, Lopez says. 'We are just seeing a wildly larger amount of sky with every image we take and getting an equal or greater amount of detail, even though the field of view is so big,' she says. The camera can take images in six filters, from the near ultraviolet to the near-infrared range. But astronomers must understand how the camera itself affects the images. Dark matter distorts the direction of photons streaming from distant galaxies, but so does the optics system, Megias Homar says. 'We really need to be sure about this. How is it affecting the light itself? If there is turbulence in the atmosphere or in the optics, a dot can become blurry,' Megias Homar says. He spent his doctoral program working on Rubin Observatory's optics system to understand this issue better. Mountaintop Observing After construction was complete, the telescope parts had to travel from California and Arizona to the top of Cerro Pachón, an 8,799-foot, seismically active peak in the Chilean Andes. Lopez and her colleagues chartered a Boeing 747 freighter jet to bring the camera from San Francisco to Santiago, Chile, in May 2024. The subsequent trip to La Serena, the city nearest the telescope's mountaintop home, required a 12-hour truck ride. Lopez monitored every step of the journey, even dealing with a trucking strike that threatened to blockade the route to Cerro Pachón. Finally, the camera made it to the literal mountaintop, where Lopez took it apart and checked everything. Teams of engineers, including Megias Homar, spent months testing the camera and its companion commissioning camera, a smaller version of the real thing that astronomers used to test all telescope systems, which went live on the sky in October 2024. The engineers shifted to nighttime work, sleeping during sunlight hours like astronomers do when they are at the observatory. 'That was the first time we saw images. For a whole month, I was going to sleep at 6 A.M. and feeling like an astronomer,' Megias Homar says. He worked with engineers and astronomers who have been planning and designing the LSST project since its inception. One person told Megias Homar they began working on it in 1996. 'I was born in 1997, so that was really humbling,' he says. Thomas has been part of the team for 10 years but got her start as an observer on a mountain next door to Rubin Observatory. 'When I joined the project, I did not appreciate how different this discovery machine or even this observatory was. I am coming from a normal, classical type of observing, which is submitting your proposal, maybe getting some time, maybe not,' she recalls. 'Bringing this amount of data to the community, to me, is just extremely rich.' For astronomers and astrophysicists, the richness is almost giddying. Rubin Observatory's 10-year main mission will provide a sort of time-lapse movie of the cosmos that will show other observatories where to look for new discoveries. A decade is not a long time in the history of the universe, but it is longer than anyone has ever stared at the sky. Telescope's First Light Galactic archaeologists like Aganze are hoping to study the history of our galaxy and how dark matter might be sculpting its evolution, just like the distant spiral galaxies Vera Rubin glimpsed a half century ago. Recent surveys from telescopes like the Gaia satellite show that the Milky Way is surrounded by streams of stars that might shed light on the dark matter halo that surrounds us. Galaxy streams can help astronomers understand when galaxy formation shuts off or how much dark matter must be around a smattering of stars for it to agglomerate into a galaxy. With Rubin Observatory, researchers should be able to see all the stars in a galactic stream, detect the stream's shape and even figure out what its associated dark matter must be like, Aganze says. And we could potentially do this for 100 or 200 galaxy streams around the Milky Way. 'If little dark matter clumps mess up the stars, we should be able to see it. We should be even able to put constraints on the dark matter—is it cold, warm or self-interacting?' Aganze says, describing three main theories for dark matter's properties. '[Rubin Observatory] is going to be great for this kind of science. We should definitely be able to march forward the limits of galaxy formation and the little dark matter halos.' The observatory will also find millions of new objects in our solar system, including 90 percent of all large asteroids that fly past Earth and thousands of tiny worlds far beyond Neptune's orbit. By essentially producing a time-lapse video, the observatory will unveil countless new transient and time-sensitive phenomena in the distant cosmos, such as quasars streaming from supermassive black holes. It will carefully scrutinize a special type of exploding binary star called a type Ia supernova that is essential for astronomy measurements and can shed more light on the nature of dark energy. Astronomers plan to share images from the camera—'first look,' as they are calling it—on June 23. Megias Homar says he is excited for the weeks ahead but admits that his first concern will be the optical system. 'I will be worried that this thing is working; that is where my mind is going to go first,' he says. And then he will turn his attention to the main mission: looking out at the cosmos. Astronomers eager to use the Rubin Observatory frequently talk about the value of just looking at the universe. Basic research is a public good, they say, that can provide new insight into our history while improving our shared future. 'It feels very much like a project based on curiosity,' Lopez says. 'Humans have always wanted to go to the top of the tallest mountain or the furthest reaches of the ocean, and this feels like one of those types of things. Let's create the coolest instrument we can to find out more about who we are.' Nobody ever promised that this generation of astronomers could unravel the mysteries of the cosmos, as Rubin herself reminds us. But right now we live in a time when we can try.
Yahoo
11-06-2025
- Yahoo
Who was Vera Rubin? Here's what to know about the astronomer behind dark matter.
Vera Rubin had just finished her ice cream when she saw something that would change astronomy forever. It was long past midnight one early morning in the 1960s, and Rubin and her colleague Kent Ford were at Kitt Peak National Observatory in the middle of the Arizona desert. That night they were tracking how hot gas from young stars circled Andromeda, the Milky Way's galactic neighbor. Rubin and Ford would trade off recording the gases' chemical fingerprints or processing photographic plates. While waiting for the plates to develop, Rubin would eat an ice cream cone. Four cones in, Rubin could draw Andromeda's rotation curve—she could plot the distance of gas clouds on an X-axis and their speeds on the Y-axis. At the time, astronomers assumed the stars circling a galaxy would act like the planets circling the sun in our solar system. Stars closer to the galaxy's center would circle quickly, while stars farther out would orbit slowly because core's gravitational pull was weaker out there. The curve, then, should start high and fall the farther the distance from a galaxy's center, astronomers assumed. Rubin never liked assumptions. She'd rather collect data, even if it met expectations. But what Rubin saw in that rotation curve didn't. The close-in and far-out stars seemed to be circling Andromeda at roughly the same speeds. The curve was flat. The ice-cream fueled find, and those that followed, forced astronomers to rethink not only what we know about galaxies but also what we know about the universe. It forced them to reimagine the fabric of the cosmos. They'd ultimately conclude that that fabric included a mysterious substance, an invisible form of matter now known as dark matter, that to this day we don't fully understand. But it wasn't just this Copernican-esque discovery of flat rotation curves that made Rubin a legend. It was the way she discovered it, the way she advocated for equality in astronomy, the way she welcomed new astronomers into the field without hesitation and kept going to the telescope well into her eighties, which is when I got to know her. It was November 2007 when I joined Rubin at Kitt Peak. No photographic plates. No winter ice cream. Just a veteran astronomer, a cub reporter, and a spiral galaxy to observe. It was in her reminiscing during those nights that I came to understand that her dark matter discovery story wasn't one of a cliché lone genius and a eureka moment. Her observations were a fold in the braid that led to dark matter becoming astronomy dogma. And, her decades of discoveries were only part of her legacy, with her outspokenness and moral compass cementing it to memory. It's this layered legacy I see in the new Vera Rubin Observatory, which will deliver its first images this month. (A century ago, this pioneering astronomer discovered what stars are made of.) Eleven-year-old Vera Rubin—Vera Cooper, then—stared at an imaginary line running down the bed she shared with her sister, Ruth, then rolled over, defeated. She was the younger of the two and was told she couldn't sleep next to the small row of windows that lined the inner wall of the bedroom and fortuitously faced north in their rented townhouse in Washington, D.C. But even from the inside edge, the starlight caught Vera's attention; she was mesmerized. Every night, she'd crawl over her sister Ruth to get a better view of the sky. 'There was just nothing as interesting in my life,' Rubin once said, 'as watching the stars.' Through her childhood in the 1930s, she would hang out by the window tracing star trails, check out library books about scientists, and build her first telescope with her dad, who worked for the Department of Agriculture. He'd also take her to the local amateur astronomy club where she heard talks by astronomers like Harlow Shapley, then the director of the Harvard Observatory. By the time Vera was in high school, she sought out cosmology books like James Jean's The Universe Around Us and Arthur Eddington's The Internal Constitution of Stars. At Vassar College, she majored in astronomy, taught herself how to observe using the college's telescopes, and took summer positions at the Naval Research Laboratory to gain experience doing science experiments. Around then, her parents introduced her to Robert Rubin. They began dating and were married in August of 1948—what many assumed was the end to Rubin's astronomy career. Vera had gotten accepted to Harvard for her master's degree. But she chose to go to Cornell University, where Bob was working on his Ph.D. in physical chemistry, instead. There were roadblocks, but Rubin found mentors in physicist Richard Feynman and astronomer Martha Star Carpenter, and her husband, who helped her launch a research project see if the universe rotated—all while they started a family. When she presented her results at the 1950 American Astronomical Society meeting in Ithaca, New York, the press was sensational. 'A young mother startled the American Astronomical Society,' the Associated Press reporter wrote. Her work challenged convention, and she would again while working on her Ph.D. at Georgetown University. Despite her research, Rubin often felt like an imposter. She earned her Ph.D. in 1954, and about a year later, took a faculty position at Georgetown. She and Bob were growing their family then, and for the next few years, she took on a variety of research projects, always analyzing others' data. Even then an imposter in her own mind, she'd advocate for her students, threatening to pull a paper from publication because the journal wouldn't print the names of the students who worked on it, for example. But, after nearly a decade, Rubin grew tired of relying on others' work to do her own. Finally, she got a break. Observational astronomers Margaret and Geoffrey Burbidge, famous for their paper on the origin of chemical elements in the life and death of stars, invited Rubin to work with them. They were also interested in galaxies and taught her the technique to calculate stars' and gas clouds' speeds. A first taste of being a real astronomer, she said. Shortly after, Rubin knew she needed access to a telescope. She went to the Department of Terrestrial Magnetism, part of the Carnegie Science Institution and talked with radio astronomers there. Then, she asked for a job. She moved into Kent Ford's office on April Fool's Day in 1965 and never left. A few years later, she and Ford discovered Andromeda's flat rotation curve. Then flat curves in other galaxies. By the early seventies, Princeton theorists Jeremiah Ostriker and Jim Peebles were running computer simulations of galaxies to figure how to get the galaxies to stay together in dizzying spirals like Andromeda. Only when the duo enveloped particles representing galaxies in spherical halos in their simulations would the galaxies cease to fly apart. They needed some extra mass to hold them together. Observations and simulations combined, astronomers knew they needed to rethink how the universe worked, and slowly the idea of dark matter took hold. By the early 1980s, consensus emerged: Dark matter existed, most conceded. (How will the universe end? The answer might surprise you.) While this shift was happening, Rubin was pushing for another—equality in astronomy. She worked on an American Astronomical Society report that highlighted issues such as discrimination in hiring, both "blatant or not", a pay gap between men and women with the same qualifications, and lower pay for married women. And, of course, she placed a cutout of a woman on the door of the historic men's-only bathroom at Palomar Observatory in California. Younger astronomers looked up to Rubin, appreciating her candor on sexism and having it all—career, family, and a loving relationship. 'For many of us, Vera had a personal impact. She demonstrated that a woman who was as cheerful, warm, generous, and down-to-earth as she was could be a successful astronomer,' astronomer Deirdre Hunter wrote not long after Rubin's death in 2016. She fostered a sense of belonging, one I felt too. It's how I, at 22, found myself at Kitt Peak with Rubin, on her final time observing, absorbing her life lessons on her grace, wit and grit. She was humble and a deep thinker. Many say she deserved a Nobel Prize. She questioned if she wanted it. 'It changed your life,' she said, and 'not always in a good way.' While studying her galaxy, I sensed of battle of wills, the tug of homelife and professional life. Her husband was ill and her childhood wonder of the universe unfulfilled. Rubin's wonder lives on in the observatory that will bear her name. It will challenge our assumptions just as she did, and I hope it will remind us that her legacy is more than a telescope. It is a blueprint for humanity—to be curious, never assume, and above all be kind. This essay is adapted from the author's book Bright Galaxies, Dark Matter, and Beyond: The Life of Astronomer Vera Rubin.
