The Vera C. Rubin Observatory in Chile has captured its first images of the night sky — marking a pivotal moment in modern astronomy. To celebrate, astronomers around the world gathered at launch events, including one held at the Institute of Astronomy (IoA) in Cambridge...
Who was Vera Rubin?
Named after Dr. Vera Rubin, a pioneer of galactic dynamics and champion of women in science, the observatory is designed to continue the work she began. Rubin’s discoveries helped reveal the presence of dark matter, the invisible glue thought to hold galaxies together.
What will the Vera Rubin Observatory do?
The observatory that bears her name is set to push cosmological boundaries. It will carry on Rubin’s work in galactic dynamics and probe the mystery of dark matter; catalogue the solar system for asteroids and comets, potentially identifying those which could be on a collision course with Earth; map the Milky Way for halos, clumps of dark matter and standard matter; and explore transients, how things like supernovae or variable stars are evolving.
How does it work?
The IoA in Cambridge was lucky enough to be visited by Freddy Muñoz, the summit mechanical engineer in Chile, who described what makes this telescope so special.
Boasting the largest camera ever built (the car-sized LSST) and an impressive 8.4m mirror telescope, the observatory has the capability to take ultra-wide, ultra high definition images of the night sky. The key to this engineering feat is a design, conceived originally in the 1990s, called a dark matter telescope. What makes it different from the previous popular design, known as the dark energy telescope, is its wide angle view. Rather than collecting information from a minuscule portion of the sky, the dark matter telescope takes in information from a large chunk and its mirror looks almost like a fish-eye lens.
How was it made?
A Herculean work effort went into the practical assembly of this telescope, as Muñoz explained at the watch party in Cambridge. His team’s work culminated in a truly remarkable finished product: a massive, agile data collecting machine. A video was shown of the nearly 400 tonne telescope actually being pushed around by hand; this incredibly heavy object had been fine-tuned perfectly to allow for easy, frictionless motion.
“A very large field of view and a very compact mechanical structure; with those abilities you can create at the same time a telescope which can look very far away, and at the same time be able to move this telescope pretty, pretty fast. You are creating a map of time, of asteroids, of galaxies and the study of our local neighbours,” Munoz told The Naked Scientists.
Previous imaging surveys could capture these hugely high definition images, but the traditional technology would take years to do it, whereas the agility of the Vera Rubin telescope means what would have taken years can now happen in just 3 days. The operation of the telescope will essentially create a time lapse video of the sky for the next 10 years. Never before have we been able to study how our universe evolves with such depth or clarity.
Why are Cambridge’s scientists interested?
The IoA’s Professor Hiranya Peiris, who specialises in cosmology, discussed how she intends to use the data flowing from the telescope in her research. She intends to convert the images into a dataset of distances, using colour to learn how far away the objects being imaged are, and therefore how far into the past we are looking. She hopes to observe the expansion and acceleration of the universe and to even spot exciting astrophysical events such as the afterglow of a neutron star merger, which has been seen only once before, in 2017. An event like this would allow us to answer questions like, "what makes gold?" and "Is general relativity accurate?"
Peiris highlighted that the observatory's greatest strength – its immense data output – will also be its main challenge. A lot of work has already gone into developing algorithms to sort through the data to pick out the most important events. A priority will be figuring out “how to find needles in a haystack; and it’s a very, very big haystack!"
“In only a few weeks of work the telescope has found more objects than other previous surveys have done in five years, and this is just the beginning,” says Muñoz.
But the opportunity to use this incredible set of data is extremely exciting, and although she is looking forward to the many amazing sights we are hoping to see, Peiris is most excited for all the things we don’t expect. This sentiment of exploration and finding something new was prominent throughout the event, with the following quote from Rubin sticking in everyone’s minds:
“Don’t shoot for the stars we know are there, shoot for the space in between because that’s where the mystery lies”
How has Vera Rubin’s legacy influenced the project?
Peiris also highlighted some of the collaborative aspects of the project. The data will be available publicly and can be seen in amazing detail on zooniverse. As the Ambassador for Chile put it, “knowledge has no gender, the universe is open to all.”
Beyond the scientific marvels, there was a strong sense of cooperation and optimism. It was noticeable that there was a diverse attendance and a lot of women present. The spirit of international cooperation were refreshing in the current climate, and mention was also made of the environment, and protecting Chile to keep viewing conditions excellent. The event fostered an inspiring atmosphere of togetherness.
What are the possible future advancements?
At the end of the launch party, Muñoz discussed some of what the telescope will be observing and ideas for the future. Since the Observatory is located in Chile, it will be observing the Southern sky. In particular it will be facing roughly towards the galactic centre. This will be incredibly useful when trying to map the Milky Way. Muñoz optimistically envisions a future with multiple observatories like the Vera Rubin globally, say 3 in the Northern hemisphere and 3 in the Southern Hemisphere, although he's realistic about the immense cost. The Vera Rubin facility alone has cost nearly $2 billion to build and operate.
But that hasn't stopped the space science community from dreaming. Already they're talking eagerly about an even larger, equally agile machine! For now though, they'll have to settle for the fantastic results already flowing from the new facility and expect the unexpected. As Muñoz presciently predicts, "It will reveal things that probably we don't know that it exists today. So this is not a project to confirm science, but to discover new things..."
