Killer asteroid-spotting software could help save the world
By Robin George Andrews
The ability of technology to solve global problems is often overhyped. But when it comes to saving the world from asteroid strikes, lines of code may prove to be our savior.
Telescopes surveying the skies for errant space rocks are overseen by astronomers, but their systematic movements are driven by ones and zeros. With so much inky sky to peruse, scientists rely on algorithms to spot suspicious and speedy objects, including asteroids that may threaten Earth.
Conventional algorithms need four images, taken during a single night, of a moving object to confirm whether it’s a genuine space rock. But new software developed by researchers at the University of Washington cuts the number of necessary nightly observations by half, boosting the ability of observatories to quickly identify these lithic projectiles. And the program, named HelioLinc3D, has already found a near-Earth asteroid that older surveys had missed.
Analyzing data from the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey, the program spotted an asteroid that ATLAS and similar surveys had failed to see — one 600 feet long, the type that could devastate a large city.
Named 2022 SF289, the asteroid is classified as “potentially hazardous,” based on its size and proximity. But although this asteroid’s closest approach is within 140,000 miles of Earth’s orbit, half the distance to the moon, there is no impact risk for the next century and very likely for many millenniums in the future.
HelioLinc3D won’t just bolster the efforts of preexisting asteroid surveys. It was specifically designed for the Vera C. Rubin Observatory in Chile. The observatory’s huge mirror, massive camera and expansive eye will see pretty much everything in the night sky in unprecedented detail, from far-flung collapsing stars to sketchy-looking asteroids swimming in our galactic backwater.
Hoping to catalog as many objects as possible, the Rubin telescope is designed to speedily sweep across the sky each night. Without HelioLinc3D, the observatory would be unable to reveal the asteroid-filled neighborhood around our planet. “The discovery of 2022 SF289 is the proof,” said Ari Heinze, the principal developer of HelioLinc3D and a researcher at the University of Washington.
The world’s family of asteroid-hunting telescopic surveys has so far found more than 32,000 near-Earth asteroids. Most of those capable of inflicting planet-scale devastation have been found because it’s easier to spot bigger rocks glinting in sunlight.
But asteroids at least 460 feet long — those with the potential to wipe out cities or small countries, should they impact Earth — are far fainter and are considerably more difficult to locate. They are mostly undiscovered at present, with about 10,500 found out of a projected total of roughly 25,000.
The four images in a single night required by conventional survey algorithms to detect asteroids aren’t always possible because of inclement weather conditions, an object’s extreme faintness or the glare of a brighter star or galaxy. And so an asteroid can be captured in multiple survey images across many nights and still go unrecognized — not ideal for planetary defense.
The Rubin Observatory, set to begin its 10-year survey of the sky in 2025, can see exceedingly faint objects, including asteroids with city-killing potential. And with HelioLinc3D, the observatory needs only two images per night, across three different nonconsecutive nights, to confirm an asteroid’s existence.
“It took us about 200 years to go from one known asteroid to a million. Depending on when we start, it will take us between three and six months to double that,” Mario Jurić, an astronomer at the University of Washington and the HelioLinc3D project’s team leader, said.
Rubin’s next-generation instruments are going to catalog not just asteroids but “all moving objects,” including comets, icy worlds beyond Neptune and interstellar entities, said Meg Schwamb, an astronomer at Queen’s University Belfast who is not involved with the work.
She added that the Rubin Observatory will be a discovery-making machine, and that HelioLinc3D “is the engine. It’s going to rewrite the solar system.” The hope is to discover, within the dark and vacant sea, myriad islands, all beguiling remnants of the solar system’s cacophonous creation.