New algorithm traps first ‘potentially dangerous’ asteroid

An asteroid discovery algorithm — designed to uncover near-Earth asteroids for the Vera C. The Rubin Observatory’s upcoming 10-year night sky survey has identified its first “potentially hazardous” asteroid, a term for near-Earth space rocks that scientists want to follow. The approximately 600-foot asteroid, designated 2022 SF289, was discovered during algorithmic testing on the road with the ATLAS survey in Hawaii. The discovery of 2022 SF289, which poses no risk to Earth in the near future, confirms that the next-generation algorithm, called HelioLinc3D, can identify near-Earth asteroids with fewer observations and more distributed than required by current methods. “By demonstrating the true effectiveness of the software Rubin will use to search for thousands of dangerous but unknown asteroids, the discovery of 2022 SF289 makes us all safer.” said scientist Ari Heinze of Rubin, lead developer of HelioLinc3D and researcher at the University. of Washington. The solar system is home to tens of millions of rocky objects, ranging from small asteroids no larger than a few feet to dwarf planets the size of our moon. These objects date back more than four billion years, when the planets in our system formed and assumed their current positions. Most of these objects are distant, but some orbit close to Earth and are known as Near-Earth Objects or NEOs. The closest of them – those whose orbits put them about 8 million kilometers from Earth’s orbit, or about 20 times the distance between the Earth and the Moon – deserve special attention. These “Potentially Hazardous Asteroids” or PHAs are systematically searched and monitored to ensure that they will not collide with Earth, a potentially devastating event. Scientists look for PHAs using specialized telescope systems such as the NASA-funded ATLAS survey, led by a team from the University of Hawaii’s Institute of Astronomy. To do this, they photograph parts of the sky at least four times a night. A discovery was made when they noticed a bright spot moving clearly in a straight line through the series of images. Scientists have discovered about 2,350 PHAs using this method, but it is estimated that at least many more are waiting to be discovered.

From its peak in the Chilean Andes, the Vera C. Rubin Observatory is expected to join the hunt for these objects as early as 2025. Funded primarily by the US National Science Foundation and the Department of Energy In the United States, Rubin observations will significantly increase the rate of discovery of PHAs. Rubin will scan the sky at unprecedented speeds using an 8.4-meter mirror and huge 3,200-megapixel camera, visiting spots in the sky twice a night instead of the four required by current telescopes . But with this novel “rhythm” observation, the researchers needed a new type of discovery algorithm to reliably detect space rocks.

Rubin’s solar system software team at the University of Washington’s DiRAC Institute has worked hard to develop such codes. Working with Smithsonian senior astrophysicist and Harvard University professor Matthew Holman, who in 2018 pioneered a new kind of heliocentric asteroid search algorithm, former Heinze and Siegfried Eggl University of Washington researcher, now an assistant professor at the University of Illinois at Urbana-Champaign, developed HelioLinc3D: code that can find asteroids in Rubin’s dataset. While Rubin was still under construction, Heinze and Eggl wanted to test HelioLinc3D to see if it could detect a new asteroid in existing data, an asteroid with too few observations to detect. discovered by conventional algorithms today. John Tonry and Larry Denneau, chief astronomers of ATLAS, provided their data for testing. The Rubin team asked HelioLinc3D to search through this data, and on July 18, 2023, they discovered the first PHA: 2022 SF289, originally imaged by ATLAS on September 19, 2022 at a distance of 13 million kilometers above Earth.