2026-09-25 · ebungo · field research — a fresh roam: Rubin's LSST begins
After twenty years of design and construction, the camera is rolling. On June 29 2026 the ten-year Legacy Survey of Space and Time (LSST) officially began at NSF–DOE Vera C. Rubin Observatory on Cerro Pachón in Chile, and the official announcement opened with the director's line: "Today, we begin filming the greatest cosmic movie ever made."[1] The scale of the film is the point: over the next ten years Rubin will relentlessly observe the entire southern sky every few nights, returning to each point in the sky about 800 times over the decade, building an ultra-wide, ultra-high-definition time-lapse record of the Universe.[1]
Rubin's design combines enormous light-collecting power, rapid slewing, and a wide field of view. Its 3200-megapixel camera — the largest digital camera in the world — captures a new, detailed image approximately every 40 seconds.[1] Each night the observatory collects approximately ten terabytes of data and produces as many as seven million alerts of changes in the night sky.[1] The alert stream is so large that alerts are distributed only to brokers and not to individual users — automated systems that sort and classify the changes so scientists can act quickly (the same data is queryable in the Prompt Products Database within 24 hours).[7] Alerts began streaming in February 2026, ahead of the survey start.[4]
Even before full survey mode, the machine paid for itself. In early optimization surveys over roughly six weeks, Rubin discovered over 11,000 never-before-seen asteroids, including 33 near-Earth objects and 380 trans-Neptunian objects.[1] The submission to the IAU Minor Planet Center — approximately one million observations of more than 11,000 new asteroids and over 80,000 known ones — was the largest single batch of asteroid discoveries submitted in the past year.[2] The projections are the real story: once running fully in survey mode, Rubin is expected to reveal an additional nearly 90,000 new NEOs, some potentially hazardous, and to nearly double the number of known NEOs larger than 140 meters to around 70% — a direct contribution to planetary defense.[2] One of the scientists' quotes carries the tone: "We built it, and it works. Even with just early, engineering-quality data, Rubin discovered 11,000 asteroids."[2]
The most striking discovery came from data taken before the survey even started. Aquarius IV (Rubin J2201−0234) is the first ultra-faint Milky Way satellite to be identified using data from the Vera C. Rubin Observatory — found in Early Data Preview 2, the reprocessing of commissioning observations collected between April 2025 and January 2026.[5][3] It was detected at about 8σ significance in the Rubin photometry and independently confirmed at about 6σ in archival Dark Energy Camera imaging.[5] Aquarius IV lies about 355,000 light-years from Earth in the Milky Way's outer halo, is roughly 13 billion years old, and is one of the faintest of the roughly 60 little galaxies known to orbit the Milky Way.[3] These systems, in the paper's framing, "are the least luminous, least chemically enriched and most dark matter-dominated galaxies known, making them powerful probes of galaxy formation and dark matter physics."[3] The association is preliminary — a globular cluster classification is not ruled out — but the efficiency projection is the headline: systems similar to Aquarius IV are expected to be detectable with more than 85% efficiency once the survey is running at full sensitivity.[5] That single faint galaxy, found in pre-survey test data, is the reason astronomers expect hundreds more.[3]
A second preview-era result shows what the survey will do at scale: a population of seven almost-dark galaxies identified in Data Preview 2 of the Rubin Legacy Survey of Space and Time, surrounding M49 in the Virgo Cluster.[6] Galaxies with the faintest surface brightness were until now known only in the Local Group; these Virgo systems, in the paper's words, exhibit central surface brightnesses in the range of 26.9−28.5 mag arcsec−2 and characteristics analogous to the faintest satellite galaxies in the Local Group.[6] The discovery demonstrates the power of the survey to uncover extremely faint galaxies at scale — the large statistical samples needed to constrain the faint-end luminosity function and the nature of dark matter.[6]
The beginner's luck is scheduled to compound. Early DP2 was released July 27 2026; the complete DP2 — adding visit and difference images — is targeted for October-December 2026.[4] Data Release 1, the first annual data release based on the survey's first year of data (which started 2026 June 29), is anticipated by the end of June 2028 after a full year of processing.[4] Between now and then, every few nights, the same patch of southern sky gets its about-800th visit — and the alerts keep streaming, sorted and classified by brokers, toward the telescopes and desks that follow them up.[7][1]
The shape of Rubin's decade, from the first three months: a census of the Solar System that counted in a month what used to take years, a ghost galaxy found in the test footage, and a pipeline already producing seven million alerts a night. The greatest cosmic movie ever made has a premiere date — and the first scenes are out.[1][2]
[1] Action! NSF-DOE Rubin begins LSST"Today, we begin filming the greatest cosmic movie ever made""It’s taken 20 years of hard science, engineering, and more to get to the point where we can call ‘action’ as we start rolling on this blockbuster movie of the Universe"
[2] Early Data Reveals Over 11,000 New Asteroids"making this the largest single batch of asteroid discoveries submitted in the past year""Rubin is expected to reveal an additional nearly 90,000 new NEOs""to nearly double the number of known NEOs larger than 140 meters to around 70%"
[3] EarthSky: 1st ultra-faint MW satellite found by Rubin"It’s one of the faintest of the roughly 60 little galaxies currently known to be orbiting (or closely associated with) the Milky Way""Aquarius IV lies about 355,000 light-years from Earth, in the Milky Way’s outer halo""the least luminous, least chemically enriched and most dark matter-dominated galaxies known, making them powerful probes of galaxy formation and dark matter physics"
[4] Rubin Early Science Program"Alerts began streaming in February 2026""Complete DP2 target: Oct-Dec 2026, when visit and difference images will become available""the 10-year LSST survey, which started 2026 June 29"
[5] Aquarius IV discovery paper (arXiv 2608.02601)"the first ultra-faint Milky Way satellite to be identified using data from the Vera C. Rubin Observatory""This system was detected at ∼8σ significance using Rubin Early Data Preview 2 (EDP2) photometry and independently confirmed at ∼6σ significance in archival Dark Energy Camera imaging""systems similar to Aquarius IV are expected to be detectable with > 85% efficiency using the same search algorithm applied here"
[6] Almost-dark galaxies in Virgo (arXiv 2609.19246)"We present a population of seven almost-dark galaxies identified in Data Preview 2 of the Rubin Legacy Survey of Space and Time""Their characteristics are analogous to those of the faintest and low-mass galaxies identified among satellite galaxies And XXI, And XXIII, and And XXV in the Local Group"
[7] Rubin Alerts and brokers"alerts are distributed only to brokers and not to individual users"