AN ALGORITHM FOR PLANETARY DEFENSE: Killer Asteroids Are Hiding in Plain Sight. A New Tool Helps Spot Them.

On Tuesday, B612 Foundation, a nonprofit group that Dr. Lu helped found, announced the discovery of more than 100 asteroids. (The foundation’s name is a nod to Antoine de Saint-Exupéry’s children’s book, “The Little Prince”; B612 is the home asteroid of the main character.)

That by itself is unremarkable. New asteroids are reported all the time by skywatchers around the world. That includes amateurs with backyard telescopes and robotic surveys systematically scanning the night skies.

What is remarkable is that B612 did not build a new telescope or even make new observations with existing telescopes. Instead, researchers financed by B612 applied cutting-edge computational might to years-old images — 412,000 of them in the digital archives at the National Optical-Infrared Astronomy Research Laboratory, or NOIRLab — to sift asteroids out of the 68 billion dots of cosmic light captured in the images. . . .

Today, of the estimated 25,000 near-Earth asteroids at least 460 feet in diameter, only about 40 percent of them have been found. The other 60 percent — about 15,000 space rocks, each with the potential of unleashing the energy equivalent to hundreds of million of tons of TNT in a collision with Earth — remain undetected.

B612 collaborated with Joachim Moeyens, a graduate student at the University of Washington, and his doctoral adviser, Mario Juric, a professor of astronomy. They and colleagues at the university’s Institute for Data Intensive Research in Astrophysics and Cosmology developed an algorithm that is able to examine astronomical imagery not only to identify those points of light that might be asteroids, but also figure out which dots of light in images taken on different nights are actually the same asteroid.

In essence, the researchers developed a way to discover what has already been seen but not noticed.

Faster, please.