The 18-story silhouette of the nearly completed Vera C. Rubin Observatory loomed above as I looked over a field of construction remnants a few weeks back. Beside me were two-ton custom jigs and dozens of shipping mounts resembling modern art. Within eyeshot were one-to-one-scale mass surrogates representing complex telescope parts and a swimming-pool-size bulletproof crate that had held the observatory’s large reflecting mirror—a 37,000-pound glass object as fragile as a teacup—on its journey across continents and waves to this mountaintop, Cerro Pachón.
This ridge, on the edge of the Atacama Desert in Chile, some 9,000 feet above sea level, is now home to three of the world’s most powerful telescopes, including Rubin. It’s also probably one of the most unforgiving locations in the world to try to build anything, let alone something as complex as an observatory. Yet these same conditions—distance from anthropogenic light sources, a mountainous altitude above the cloud line, a crisp desert atmosphere—provide the baselines for Rubin to access the faintest of faint celestial objects.
The first mind-bending images taken by the observatory were released today in the tradition of “first light,” a new observatory’s ceremonial opening. The images represent a decades-long effort by a globally dispersed team of astrophysicists, data scientists, engineers, administrators, machinists, welders, bus drivers, cooks, and thousands of others completing one of the most sophisticated objects that humans have ever built.
Since 2022, I’ve been the observatory’s artist in residence, and I’ve been closely shadowing Rubin’s work since 2017 as part of a planetary sculpture I’m making called Twelve Earths. As an artist, I find it hard not to imagine Rubin as a sculptural entity, an object that in its complexity has stretched the limits of what Earth’s storehouse of materials can accomplish. Yet for all its sheer matter—steel, glass, silver, aluminum, copper, ferroconcrete, silicon—the observatory seems to lift off into a mytho-poetic dimension.
Rubin is what’s called a “survey telescope,” making its principal artifact a map. In this case, the most elaborate, 4-D, data-dense, Borgesian map of the cosmos in motion that humans at this moment conceivably can make. It will catalog 37 billion discrete astronomical objects, revisiting them every three nights again and again, for 10 years.
To process this enormous volume of information, arguably astronomy’s first full-throated foray into big data, a physical data pipeline was built to connect the observatory to the SLAC National Accelerator Laboratory in California, where images collected from the summit will be analyzed and delivered to the inboxes of astronomers around the world—approximately 10 million alerts issued each night. In this way, Rubin is an amplifier system for existing observatories around the world: It will hand off precise coordinates so they can linger on supernovas, tidal-disruption events, gamma-ray-burst afterglow, interstellar visitors, neutrino triggers, comets, and more. Some people also liken the observatory to a planetary insurance policy, detecting near-Earth objects before they could ram into us. Others are predicting that it could generate evidence that points toward alien intelligence. Among the many charismatic analogies for Rubin, my current favorite imagines the observatory as the largest, most elaborate movie camera shooting a cosmic film that will take 10 years to complete.
Rubin is also a rare scientific megaproject that feels excitingly relatable. Instruments such as particle accelerators, neutrino detectors, and even radio telescopes might command our awe, but they roam in realms far outside sensorial experience. At its core, Rubin is an optical telescope. This links it to a long continuum of prosthetic tools that help our bodies better do what they already do naturally—see and process light.
Still, witnessing the observatory’s core photon-capturing operations means taking in an unusual amount of choreography. Tons of steel and glass whirl with a precision that would make Swiss watchmakers envious. Enclosed within Rubin’s dome—a 360-degree rotating structure as big as an apartment building—is a gimbal-esque object called the telescope mount assembly. The machine is anchored to an island of reinforced concrete that stretches deep into the mountain, helping the telescope achieve absolute stillness for its balletic operations. The telescope assembly pivots, torques, and tilts with vertigo-inducing velocity while also balancing a camera as big as a car and an array of three massive mirrors that, together, are heavier than a tractor trailer.
Rubin’s mirrors—its de facto spiritual center—live in a zone of rare alchemic perfection. Each is the result of years of jewel-like polishing and honing. The mirrors work in unison, in a unique stacked system, to coax Rubin’s gaze to a functional limit, gathering as much primordial light as possible. Riding under the mirrors is a system that autocorrects the tiny imperfections that gravity secretly imposes on tons of ultra-stiff, honeycombed glass. Every 40 seconds, as the mirrors are repositioned for their next long exposure, the actuators perform a new calculus to make a reflective surface that’s seemingly already perfect even more so. An infinitesimally small aberration here or there can foul up an otherwise good night of astronomy, if you’re hoping to catch a glimpse of an object a billion light-years away.
After the photons bounce among Rubin’s mirrors, their final stop before being transformed into data is the world’s largest digital camera. It has 189 CCD sensors producing massive 3.2-gigapixel images. Four hundred ultra-high-definition monitors would be needed to see the pixels generated in a single 30-second exposure.
In the dusk at Cerro Pachón, the field of construction bits and pieces began to feel like an archaeological site, its objects becoming artifacts of the observatory’s origins. The sun was waning toward the Andean peaks, bounding like waves toward the Pacific. Framing the view were acres of sky crossfading to the deepest cerulean on the horizon, hinting at the starscape waiting for its nightly reveal.
A gleam of light careened off the construction debris and ricocheted into my eyes. The surplus of photons triggered a signal through my optic nerves, and in a millisecond, a web of electrical signals reached across my brain, branching into billions of neurons and trillions of synapses. Together, they formed a unique constellation, a thought: that this same light staggering my sight—in fact all light, all around us, everywhere—was composed of not only nine-minute-old local sunlight but also light from billions of the faintest space objects. Rubin hopes to tally these same sorts of deep-space particles, the kind that all of Earth is constantly microdosing, phantom starlight from the farthest reaches of the universe.
My eyes found a place to rest on Rubin. The thought melted into another: The tiny sliver of photons that somehow do find this observatory will be pretty special.
Regaining a bit of balance, I could make out Aaron Roodman, the deputy director of construction and the camera-program lead, walking in my direction with a small team from SLAC. I fell into step with the group, headed to the cafeteria, and asked how the afternoon went. “Really well. It’s time to chill the camera’s CCDs to 100 degrees below Celsius,” Roodman said. “The sensors each generate a tiny bit of light—it’s something we call ‘dark current.’ Chilling everything makes the electrons behave less energetically. It makes everything darker.”
Our conversation followed us into dinner, which we finished quickly: The team had much to wrap before the observing crew arrives for its night shift. On the walk back to the observatory, our group reached a familiar bend in the path. We pivoted slightly and were met with a panoramic Andean vista, the sun illuminating Rubin’s facade in the last of the evening’s golden-red glow. Our group paused to linger. “This never gets old. Just incredible,” Roodman let out.
He was right: The sight, in its totality of overwhelming landscape and human achievement, was awesome. Here on a secluded peak, people have made real a thesis about the limits of long-form human coordination while managing a psychedelic balancing act, calibrating a machine to the smallest units of measurement in order to seek out the biggest objects in the universe.
In the distance, I could see a small crew putting the final touches on a safety railing near Pachón’s ridgeline. Someone held a pole while someone else attached it to another. These were two touchpoints within a continuum of billions of others—a typed-out line of code, a welded seam, a bolt tightened—each moment of contact balanced by those of ancestors who’d learned to sharpen flint, fuse glass, or dream in femtoseconds.
Here on this summit, it was not much of a sideways leap to imagine the observatory as a mountaintop cathedral nested above the clouds. One generation’s gift to the next—a modern iteration of an ancient sky ritual held in the darkest hours—to sustain communion with the oldest cosmic light, rendering the invisible visible for everyone to see.
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