My Favorite Bonkers LSST Facts

The Legacy Survey of Space and Time (LSST) is a 10-year survey using the Vera C. Rubin Observatory. Rubin achieved first light in June 2025 and released Data Preview 1 shortly after; the survey is now underway. The current schedule can be found at ls.st/dates.

This survey will provide us with a truly impressive dataset with which to learn about the universe. Some of my favorite LSST numbers are:

• During the first year of operations, LSST will catalog more unique objects than all previous astronomical observations combined.
• Each night we expect 10^6 astrophysical transients to be detected and alerts to be sent out within 60 seconds of taking an image.

For the full 10-year survey, we expect to catalog:

• 20 × 10⁹ galaxies (1% of galaxies in the observable universe)
• 17 × 10⁹ resolved stars
• 10 × 10⁶ supernovae (each wide image will likely contain 160 active supernovae)
• 6 × 10⁶ orbits of solar system bodies
• 10 time-domain events with alerts within 60 seconds

The 10-year survey can be thought of as reaching:

• Hubble Deep Field depths (g~27.4) over ~20,000 sq deg (wide component)
• Hubble Ultra-Deep Field depths (g~28.7) over ~50 sq deg (deep component)

Here is a selection of my favorite videos/photos taken during the construction/commissioning process:

• Mirror Coating
• Camera Install
• Primary Mirror Install
• Horizontal rotation

And here are the first light videos:

• Asteroids
• Virgo Cluster
• Trifid Nebula