Vera Rubin Observatory begins decade-long survey of the southern sky

Vera Rubin Observatory begins decade-long survey of the southern sky

The Vera C. Rubin Observatory in northern Chile has officially launched the Legacy Survey of Space and Time (LSST), a 10-year project designed to create a massive time-lapse record of the southern sky. The survey began on Tuesday, June 30, after a period of system optimization and technical reviews.

Perched on the 8,800-foot-high (2,682-meter-high) summit of Cerro Pachón mountain, the facility was jointly funded by the U.S. Department of Energy and the National Science Foundation at a cost of approximately $800 million. The location was selected for its dry air and dark skies.

At the center of the operation is the world’s largest digital camera, weighing 6,600 pounds and roughly the size of a small car. Built by the SLAC National Accelerator Laboratory, the 3,200-megapixel camera will capture an image every 30 to 40 seconds of nighttime. These images will be processed using six different colored filters, allowing the telescope to scan the sky 100 times faster and with a field of view 100 times larger than similar telescopes, according to Željko Ivezić, head of the LSST.

"Today, we begin filming the greatest cosmic movie ever made,"

Brian Stone, acting director of the National Science Foundation, via statement

The observatory utilizes an 8.4-meter-wide starlight-gathering mirror to track the evolution of celestial objects. By returning to the same patches of sky hundreds of times over the decade, the LSST will create a living image of how galaxies, asteroids, and supernovae morph and move. The survey aims to build a new inventory of the Milky Way and our solar system while observing the distorted light of distant galaxies to study dark matter.

The scale of data collection is unprecedented. Each night, the facility will collect 10 to 20 terabytes of data. During its first year, the Rubin is expected to gather more data than all previous visible-light telescopes combined. To manage this volume, researchers will use machine learning and AI to filter the information. The system is expected to dispatch about 7 million alerts nightly to flag explosions or interesting movements for scientists to investigate.

One of the primary scientific goals is resolving the mystery of dark energy and the accelerated expansion of the universe. Željko Ivezić stated that within five to seven years, the data should allow scientists to distinguish between two major hypotheses: whether dark energy is a real phenomenon or if the laws of gravity at cosmic scales have been misunderstood.

The observatory also focuses on "transients" — flashes of light that appear and fade quickly. This includes gamma-ray bursts, which can result from colliding neutron stars or black holes. Additionally, the survey is expected to discover millions of new asteroids, including those that may be on collision courses with Earth.

The project did not begin immediately after the facility opened its eye to the sky roughly a year ago. While first images were released in June 2025 — showing the Trifid and Lagoon nebulas and structures in the Virgo galaxy cluster, the official start of the LSST was delayed from early 2026 due to extended checkouts. Željko Ivezić noted that the decision to begin was based on a review of calibration accuracy, system uptime, reliability, image quality, and effective survey speed.

Preliminary images taken as early as April 15, 2025, have already detected 11,000 new asteroids and dozens of other solar system objects. The final dataset will eventually contain trillions of measurements of billions of objects, which will be made available to both the public and the scientific community through regular data releases.

The data will be hosted at the U.S. Data Facility at SLAC, where the Dark Energy Science Collaboration will use the measurements to determine fundamental cosmological parameters.