Software that detects asteroids could save the world – 8/10/2023 – Science

Technology’s ability to solve global problems is often overstated. But when it comes to saving the world from asteroid strikes, lines of code can end up being our salvation.

Telescopes that scan the sky for errant space rocks are monitored by astronomers, but their systematic movements are driven by ones and zeros.

With so much dark skies to examine, scientists rely on algorithms to identify suspicious objects moving at high speeds, including asteroids that could endanger Earth.

To confirm that a moving object is a genuine space rock, conventional algorithms need four images taken during a single night. But new software developed by researchers at the University of Washington cuts the number of nighttime observations required in half, boosting observatories’ ability to quickly identify these lithic projectiles.

Called HelioLinc3D, the program has already found an asteroid that approached Earth and that had gone unnoticed in previous surveys.

Analyzing data from the NASA-funded Atlas Survey (an acronym for the Earth Impact Asteroid Impact Latest Alert System), the program identified an asteroid that Atlas and similar observatories had not spotted – a 183-metre-long object, of the type that would be capable of destroying a large city.

The asteroid has been named 2022 SF289 and has been classified as “potentially hazardous” based on its size and proximity. But while the closest it will come to us is 140,000 miles from Earth’s orbit — half the distance between Earth and the Moon — there is no risk of an impact for the next hundred years, and probably not for many millennia to come.

HelioLinc3D will not only bolster pre-existing asteroid research efforts. It was designed specifically for the Vera C. Rubin Observatory in Chile. This observatory’s massive mirror, massive camera, and expansive lens will see virtually everything in the sky in unprecedented detail, from distant collapsing stars to suspicious-looking asteroids swimming in our galactic backwater.

Hoping to catalog as many objects as possible, the Rubin telescope is designed to quickly scan the sky each night. Without HelioLinc3D, the observatory could not reveal the asteroid-filled region around our planet.

“The discovery of 2022 SF289 is proof of that,” said Ari Heinze, lead developer of HelioLinc3D and a researcher at the University of Washington.

The family of global telescopic asteroid surveys has already found more than 32,000 near-Earth asteroids. Most of the ones that would be capable of wreaking havoc on a planetary scale were found because larger rocks are easier to see glistening in sunlight.

But asteroids at least 140 meters across — ones that have the potential to destroy cities or small countries if they collide with Earth — are much less visible and considerably harder to locate. Most of them have not been discovered so far: about 10,500 have been found out of a projected total of 25,000.

It is not always possible to obtain the four images taken in a single night required by conventional search algorithms to detect asteroids, due to improper meteorological conditions and the fact that the object is very dim or the strong glow of a brighter star or galaxy.

Thus, an asteroid can be captured in several survey images over many nights, but still not be recognized. It’s not an ideal situation, in terms of defending the planet.

The Rubin Observatory, which is due to begin its 10-year survey of the sky in 2025, is able to see objects that shine very dimly, including asteroids with the potential to destroy cities. And with HelioLinc3D, the observatory only requires two images per night, over three non-consecutive nights, to confirm the existence of an asteroid.

“It takes us about 200 years to go from one known asteroid to 1 million. Depending on when we start, it will take between three and six months to double that number,” said Mario Juric, an astronomer at the University of Washington and team leader on the HelioLinc3D project.

The Rubin Observatory’s next-generation instruments will 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 not involved with the work. .

She added that the Rubin Observatory will be a discovery machine and that HelioLinc3D “is the engine of the machine. It will rewrite the solar system.” The hope is to discover many islands within the dark and empty sea, all of them fascinating remnants of the dissonant creation of the solar system.

Translated by Clara Allain