After nine years of construction, a state-of-the-art telescope connected to the world’s largest camera is set to change our understanding of astronomy.
Perched atop a barren mountaintop in the arid Chilean desert region of Coquimbo, the Vera C Rubin Observatory looks literally out of this world.
With a sleek, futuristic frame in the mountain’s groove on Cerro Pachón, the observatory is characterized by a distinctive compact, rotating dome-like shape that splinters into a myriad of angles.
The unusual, isolated structure is the heart of a $1.9 billion project set to begin in early 2025 to map the skies.
“This is a very special telescope, unlike others because it will take a survey of the night sky. It will move a lot,” said Jacques Sebag, the site’s compilation integration and verification manager.
Using a laser pointer, Sebag points out the width of the telescope’s 8.4 meter diameter mirror, equipped with a modern 3,200 megapixel camera.
It was designed to capture an unprecedented amount of astronomical data in a 10-year survey called the LSST (Legacy Survey of Space and Time).
“Before that, telescopes saw small parts of space, looked at very specific information for a very specific problem, but this is like a lighthouse,” he said, spreading his hands to convey the vast expanse of the sky. “It [illuminates] different parts of the sky. It is the fastest moving telescope ever built.”
The telescope is characteristically squat and compact in design, allowing it to constantly move and observe changes, recording what astronomers call “the passing sky”.
Each night it will detect 10m events, ranging from asteroid motion to supernova explosions.
“It’s a very rich data set, it has something for almost everyone in astronomy,” said Frossie Economou, the site’s technical manager for data management.
“We will answer questions about the universe from our local neighborhood – the solar system – to the creation of time, out there in the far reaches.”
Construction of the observatory, named after the North American astronomer who proved the existence of dark matter, began in 2015.
The project is primarily envisioned to address uncertainties about what constitutes dark matter and dark energy more than 70% of the universe.
Chile is home to a number of the world’s most important astronomical centers. The height above sea level of the Andes mountains that surround the country, and the lack of light pollution in the sparsely populated desert areas, make for ideal air shifting conditions. The Rubin site enjoys an average of 256 clear nights per year.
With the completion of the Rubin project, Chile will become the leading destination of astronomical observation, generating approximately 70% of the data seen from Earth by 2025.
Steve Heathcote is the director of Cerro Tololo, a neighboring observatory that conducted studies that serve as a precursor to Rubin.
The telescopes at Cerro Tololo were integral to the discovery of the universe’s accelerated expansion, work that won the Nobel Prize for astrophysics in 2011.
Heathcote is hopeful that Chilean skies will once again help unlock more of the mysteries surrounding the creation of our universe.
“There is enough uncertainty in current measurements that you can fit something else in,” he explained, referring to our understanding of the Big Bang and universe expansion. “I think with Rubin they’ll be able to find the mistakes to the point where you can be sure.
“It could challenge Einstein’s theory of relativity. It can challenge fundamental things in physics.”
In 10 years, the LSST will generate a staggering 60 petabytes (60,000,000 gigabytes) of data through 2m images. The United Kingdom is responsible for processing approximately 25% of this data.
Aprajita Verma is based at the University of Oxford and is Rubin’s International Program Coordinator. She refers to the LSST as “the greatest movie of heaven that mankind has ever made”.
“I find it overwhelming. It will truly revolutionize our view of survey astronomy and understanding of the billions of objects we are going to see.”
The excitement of the project ripples through the global astronomical community, but is equally felt locally.
Claudia Llanquitruf has been involved in the construction of the site’s revolving dome since 2019.
She runs a company usually tasked with mining projects, based in the city of La Serena, about two hours from Rubin.
Llanquitruf is in awe of the site.
“I know what this project means, and all the studies it will generate. It’s an honor to work here.”