On a dark mountaintop in Chile, the world’s largest digital camera has begun filming its masterpiece.
This Tuesday (June 30), scientists with the Vera C. Rubin Observatory announced that the facility’s ambitious Legacy Survey of Space and Time (LSST) officially began. Every night for the next 10 years, the observatory’s car-size LSST Camera will capture a 3,200-megapixel image of the southern sky — then another, then another, slowly filling in a mosaic of the universe 30 seconds at a time.
“In a sense, we’re taking a digital color motion picture of the universe,” Tony Tyson, a professor of cosmology at the University of California Davis and LSST’s chief scientist and former founding director of the Rubin Observatory, told Live Science.
Strafing across the sky in stop-motion, the survey is expected to spot between 7 million and 8 million changes among the stars each night — from flashing supernovas and streaking comets to colliding galaxies and dim, tumbling asteroids. Within minutes of each exposure, alerts to any peculiar changes will become publicly available for astronomers and space enthusiasts around the world to study.
“Rubin is an automated facility, so scientists don’t come here to use it,” Tyson said. “But tens of trillions of observations is enough data for everybody in the world.”
Tyson is hoping the firehose of data will unmask theinvisible 95% of the universe that is composed of dark matter and dark energy.
While there are still some technical bugs to work out — and the looming threat of ultra-bright corporate satellites to contend with — Tyson and his colleagues are ready to roll out the survey, “gradually increasing our sky area and image quality” over the next few months, he added.
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Live Science spoke with Tyson about the LSST and what it may find in the coming years.
Brandon Specktor: You’re about to spend 10 years observing the southern sky with the largest digital camera ever. What will a typical night of the survey look like?
Tony Tyson: In a sense, we’re making a digital color motion picture of the universe. We’ll take thousands of 30-second exposures every night. Within two minutes of the shutter closing on an exposure, we will process all the data, [compare] it from the archival sky of that piece of the sky, and — if something explodes, or pops off, or moves in the sky in a way we don’t understand — issue an alert. The alerts go to the world.
I made the decision early on to make the data available to everyone. The alerts will also go to eight data brokers, which specialize in things like cosmology, supernovae, etc., and the public can sign up to the feed from their favorite brokers.
BS: Which feed will you be watching most closely?
TT: My most interesting data broker is one which will come up with a classification of “unknown.” I’m more interested in the unknown, unclassifiable things that go on in the universe. But there’s a sort of a live stream of catalog information that’s going to be available to people — and we’re excited for writing up a lot of new discoveries.
My hope at this time is that we will discover something unexpected that will revolutionize astronomy. I think it’s more than a hope, I think it’s a guarantee.
Tony Tyson is an astronomer at the University of California, Davis, and the founding Director of NSF–DOE Vera C. Rubin Observatory.
(Image credit: NSF–DOE Vera C. Rubin Observatory/NOIRLab/SLAC/AURA/G. Watry)
BS: What kind of revolution would that be? Is there one big question you hope Rubin will answer?
TT: I’m a cosmologist, so my hope is that we’ll get closer to understanding the physics of dark energy and dark matter.
But to be frank, I think we’ll be remembered 100 years from now for something else in addition. And discovering something totally new in the time domain, something that blows our minds, that we did not expect — some kind of new object that’s out there. There’s examples of this in radio astronomy with the FRBs [fast radio bursts], for example. And I think that that’s going to be how we will be remembered.
My hope at this time is that we will discover something unexpected that will revolutionize astronomy.
Tony Tyson, LSST Chief Scientist
BS: The Rubin Observatory observes in optical light. Are there any strange optical phenomena you have your eye on?
TT: There’s already a pretty strong hint, actually, that there is a population of very faint bursting objects that just pop off. The ones we know about are typically pretty bright — supernovae, which last for a long time, and gamma-ray bursts, which are bright but they don’t last very long. But there’s a big question mark in this unique area that we’re going to explore, of faint things that are very short-lived. And there’s evidence now from a team in Japan that there is a population of very faint things that explode just once. They don’t repeat. And so I’m keeping my eye on that.
A small section of the Virgo Cluster revealed in Rubin’s debut images. The first images, released in June 2025, capture more than 10 million galaxies.
(Image credit: NSF–DOE Vera C. Rubin Observatory)
BS: What are the Rubin Observatory’s main science goals?
TT: There’s a lot of areas of science that we can address — and that was really the main selling point for us with the agencies. For one, we’ll be looking at cosmology and the history of the expansion of the universe. Just by itself, we will have enough data to measure key parameters in cosmology to eliminate models of dark matter and dark energy, which is exciting.
Another area is looking at new kinds of stars in our galaxy, so we can look at the history of our galaxy and the history of star formation in our galaxy. At even lower redshift, an interesting area is looking at both comets and potentially Earth-threatening asteroids. Every night we detect about a thousand new asteroids.
And we will be able to uniquely look for those, if we can get rid of the interfering low-Earth-orbiting satellites, which really make that impossible. And so I’ve been unfortunately sidetracked into worrying a lot about that in the recent year.
BS: Are you talking about companies like Reflect Orbital, which essentially want to put giant mirrors in low Earth orbit? We’ve written about how satellites like that could totally compromise the LSST.
Yes. There’s a proposed class of extremely ultra-bright satellites that are going to be launched that are incompatible with the LSST science, totally incompatible. The skies will no longer be dark for anybody, anywhere.
Reflect Orbital is one example. The other example is these orbiting AI [artificial intelligence] computational centers, which will be exceedingly bright. We’ve met with all these companies. They say that they feel our pain, but their board of directors or their investors say that they’re going to go forward.
I’ve been working with SpaceX, though. They’re really trying very hard to eliminate some of these effects, but nothing is perfect. It’s going to be tough.
The Vera C. Rubin Observatory sits on a mountaintop in Chile under famously dark skies. It’s view of the universe will be unmatched, if bright corporate satellites don’t ruin the view.
(Image credit: Hernan Stockebrand)
BS: So if these companies are moving forward, what are you going to do?
What I’m trying to do is work very closely with Congress and the American Astronomical Society and other bodies — the United Nations, the FCC [Federal Communications Commission] — to see what we can do.
I’m inherently an optimist. I think the Reflect Orbital is a failed business model, but they’re going to try doing it anyway. So they’ll put a lot of junk up there for a while.
BS: I truly wish you the best with that. But since you’re an optimist, let’s end on something positive. You’ve championed this observatory for more than 20 years — first as its founding director and now its chief scientist. How does it feel now that the LSST is finally operational?
It’s quite gratifying, after all this time, to have something that actually works. It’s a hugely complicated system, and nothing so complicated as that works perfectly all the time.
I was the original founding director, I am now the chief scientist, and it is my day job to worry about what’s going wrong with this or that. And there’s a laundry list of things that we’re worried about. But it’s working, and it’s working quite well. And so that’s quite gratifying.
Editor’s Note: This interview has been condensed and edited for clarity
