6/17/2025 Debra Levey Larson
Written by Debra Levey Larson
Later this year, a new facility is expected to come online that will change the way we look at the solar system. The Vera C. Rubin Observatory is the fastest moving telescope equipped with the world’s largest digital camera. A single image from the telescope covers a patch of sky roughly 40 times the area of the full moon.
Together, this wide-fast-deep system will spend the next 10 years observing the night sky to produce the Legacy Survey of Space and Time. This will be an unprecedented time-lapse movie of the cosmos and a powerful dataset to map the solar system.
Led by Queen’s University’s Meg Schwamb, researchers around the globe created innovative new open-source software called Sorcha to predict what discoveries are likely to be made. Sorcha is the first end-to-end simulator that ingests Rubin’s planned observing schedule. It applies assumptions on how Rubin Observatory observes and detects astronomical sources in its images with the best model of what the solar system and its small body reservoirs look like today.
Siegfried Eggl, assistant professor in the Department of Aerospace Engineering in The Grainger College of Engineering at the University of Illinois Urbana-Champaign and his Ph.D. student Sam Cornwall are members of the team that developed Sorcha.
“Only by debiasing LSST’s complex observing pattern can we turn raw detections into a true reflection of the solar system’s history - where the planets formed, and how they migrated over billions of years. Sorcha is a game changer in that respect,” Eggl said.
Cornwall described some of the challenges he faced in in his work on Sorcha.
“It’s a bit tricky to handle data at this scale,” Cornwall said. “There’s a massive amount of information that’s going to be produced, but there’s also all the stuff that you don’t see but still have to simulate to the same level, because really you don’t know that you can’t see something until you don’t see it. There’s a whole lot of the smaller, fainter asteroids, which you sometimes can easily say will never be seen. But other times it takes a lot of number crunching to be sure, because they’re often only visible for short periods of time, depending on the configuration.”
The Sorcha code is open-source and freely available with the simulated catalogues, animations, and pre-prints of the papers publicly available at https://sorcha.space. By making these resources available, the Sorcha team has enabled researchers worldwide to refine their tools and be ready for the flood of LSST data that Rubin will generate, advancing the understanding of the small bodies that illuminate the solar system like never before.
Rubin Observatory is scheduled to unveil its first spectacular imagery at its “First Look” event on June 23, offering the world an early glimpse of the survey’s power. Full science operations are slated to begin later this year.