Rubin Observatory Found 11,000 New Asteroids Before Its Survey Even Began

A telescope that is still warming up usually produces test images and apologies. Rubin Observatory produced a few thousand rocks.

• Rubin’s early data revealed over 11,000 previously unknown asteroids, announced April 6, 2026 ^[1].
• The haul includes 33 near-Earth objects, none a threat, the largest about 500 meters wide, and 380 icy bodies beyond Neptune ^[2].
• About six weeks of operations produced one million observations, detecting the 11,000 new asteroids and 80,000 already known ones ^[2].
• Rubin’s alert system produced 800,000 alerts on its first night, February 24, 2026, and is expected to reach up to 7 million per night ^[3].

The numbers

In its early observations, the Vera C. Rubin Observatory in Chile detected over 11,000 previously unknown asteroids, a result led by Mario Jurić and the Rubin solar system group at the University of Washington. Jurić called it “just the tip of the iceberg” and proof that “the observatory is ready” ^[1]. The announcement came on April 6, 2026 ^[1].

Over roughly six weeks, Rubin made one million observations and picked out the 11,000 new asteroids along with 80,000 already known ones. Among the newcomers are 33 near-Earth objects, none currently a threat, the largest about 500 meters across, and 380 trans-Neptunian objects, including two on extremely elongated orbits that carry them to about 1,000 times Earth’s distance from the Sun ^[2].

The scale of the sky-watching

Rubin is built to compare the sky with itself. The observatory captures a new patch of sky roughly every 40 seconds, ships the data to SLAC in California, compares each image against earlier templates and publishes an alert within about two minutes of any change ^[3]. Its first public alerts went out on February 24, 2026, with 800,000 alerts that night, and the stream is expected to reach 7 million per night ^[3]. Nine broker platforms, including ALeRCE, ANTARES and Lasair, filter and classify the flood for scientists ^[3].

How Rubin finds asteroids so fast

The discovery came from the Simonyi Survey Telescope at Rubin Observatory on Cerro Pachón, Chile, which is planned to run a ten-year survey; the team, led by Professor Mario Jurić of the University of Washington, described the announcement as the first large submission after Rubin First Look, and said it is just the tip of the iceberg and shows the observatory is ready ^[1][2]. Before this, about 5,000 trans-Neptunian objects had been found over three decades, and two newly discovered ones reach roughly 1,000 times farther from the Sun than Earth does at their greatest distance, placing them among the 30 most distant minor planets known ^[2].

The alert system works at a different scale. Rubin captures a new patch of sky about every 40 seconds, produces about 10 terabytes of images a night, and issues public alerts within two minutes, which nine official broker platforms, including ALeRCE, Fink and Lasair, filter and classify with machine learning ^[3]. Rubin could eventually find nearly 90,000 new near-Earth objects and raise the share of known near-Earth objects larger than 140 meters to about 70 percent ^[2]. As Jurić put it, what used to take years or decades to discover Rubin will unearth in months ^[2].

What changes

Jurić’s forecast is the one to remember: “What used to take years or decades to discover, Rubin will unearth in months” ^[2]. The project could eventually discover nearly 90,000 new near-Earth objects and push the share of known objects larger than 140 meters to roughly 70 percent ^[2]. That does not mean a bigger risk. It means a sky we can finally see.

Questions readers ask

How many asteroids did Rubin discover?

More than 11,000 previously unknown asteroids in early data, including 33 near-Earth objects and about 380 trans-Neptunian objects ^[1][2].

Are any of the new near-Earth objects dangerous?

None currently poses a threat, according to Sky at Night’s report; the largest is about 500 meters wide ^[2].