After years of construction, calibration, and a long shakedown cruise on the summit of Cerro Pachon in Chile, the NSF-DOE Vera C. Rubin Observatory has stopped rehearsing and started rolling. On June 30, 2026, the observatory officially began the Legacy Survey of Space and Time, or LSST, the decade-long project it was built to run. Commissioning is over; the review is signed off; Rubin is now in production.
"Today, we begin filming the greatest cosmic movie ever made," said Brian Stone, who is currently performing the duties of the vacant National Science Foundation director role, marking a start date that astronomers have been circling on their calendars for the better part of a generation. It is worth being precise about what changed on that date. Rubin has already been taking data during its optimization phase, and it has already been productive. What began on June 30 is the full, formal science survey itself: the systematic, night-after-night program that will run for ten years.
What the survey actually does
The mechanics are almost deceptively simple to describe. Rubin's camera captures a new image of the sky roughly every 40 seconds. It sweeps across the entire southern sky every few nights, then does it again, and again, for a decade. By the time the survey wraps, each point on the sky will have been observed around 800 times. Stack all those exposures together and you get an extraordinarily deep still image of the universe. Play them back in sequence and you get a time-lapse of the changing sky, which is the part that makes Rubin genuinely new rather than merely large.
The instrument doing the filming is the largest digital camera ever built for astronomy, a 3,200-megapixel behemoth. CNN pegs its weight at about 6,600 pounds, which is a useful reminder that this is a piece of industrial hardware and not a consumer gadget. Each night it generates roughly 10 terabytes of data. Over ten years that adds up to catalogs of astronomical objects released to the community, the raw material for a decade of science.
Seven million alerts a night
The number that best captures Rubin's ambition is not the pixel count. It is the alert rate. Because the observatory keeps re-imaging the same sky, software can compare each new frame against a reference and flag anything that has changed: something that moved, brightened, dimmed, or appeared out of nowhere. Rubin is expected to issue up to 7 million of these change-alerts every single night.
That firehose is aimed squarely at the transient and time-variable universe, which includes supernovae, variable stars, and the moving points of light that turn out to be asteroids. The survey's early performance suggests the plumbing works. During its optimization phase alone, Rubin turned up more than 11,000 previously unknown asteroids, among them 33 near-Earth objects and 380 trans-Neptunian objects out in the cold, distant reaches of the solar system.
"It's taken 20 years of hard science, engineering, and more to get to the point where we can call 'action,'" said Phil Marshall, deputy director for Rubin operations at SLAC. Rubin Director Bob Blum and LSST lead Zeljko Ivezic have shepherded the observatory to this point, and the sheer volume of discovery arriving before the official start is the clearest possible evidence that the system is ready for the real thing.
The science menu
Rubin was not built for a single headline result, which is part of why it took so long to build and so many institutions to pull off. As the University of Washington, whose researchers helped build the survey's alert pipeline and software systems, frames it, the LSST is essentially a decade-long inventory project on two very different scales at once.
Close to home, it will catalog the solar system and the Milky Way in unprecedented detail, cataloging asteroids and comets and mapping the structure of our own galaxy. Far from home, it will probe the two biggest open questions in cosmology: the nature of dark matter and dark energy. The observatory is named for Vera Rubin, the astronomer whose work provided some of the most persuasive evidence that dark matter exists, so the assignment is fitting. CNN notes the survey will spend its ten-year run chipping away at the mystery of dark matter, and dark energy sits right alongside it on the agenda.
On the data side, Fermilab leads data management and processing for the LSST Dark Energy Science Collaboration, the group tasked with squeezing cosmological constraints out of the galaxies Rubin will image. That division of labor is the point: no single lab could handle a 10-terabyte-per-night instrument, so the project is distributed across a network of institutions, with University of Washington researchers building the alert pipeline that flags what has changed and Fermilab helping turn the resulting torrent into usable science.
Why It Matters
Most major telescopes are pointed instruments. You apply for time, you observe your target, you go home. Rubin inverts that model. It observes everything, all the time, and hands the resulting data to the entire community. That changes what is possible in a specific way: instead of deciding in advance what is interesting and looking only at that, astronomers get a continuously updated map of the whole southern sky and can go find the interesting things after the fact, including things nobody thought to look for.
The up-to-7-million-alerts-a-night figure is the practical face of that shift. It effectively creates a real-time notification service for the changing universe, and it will surface events that would otherwise have flickered past unseen, from distant supernovae to hazardous near-Earth asteroids. The 11,000 asteroids found before the survey even officially started are a preview of how much low-hanging discovery has been sitting in plain sight, waiting for an instrument fast and wide enough to catch it. For planetary defense, for cosmology, and for the study of anything that varies in time, the next ten years just became considerably more interesting. The cosmic movie is now rolling, one 40-second frame at a time.
