Asteroid Terrestrial-impact Last Alert System

The Asteroid Terrestrial-impact Last Alert System (ATLAS) is a robotic astronomical survey and early warning system optimized for detecting smaller near-Earth objects a few weeks to days before they impact Earth.

Funded by NASA, and developed and operated by the University of Hawaii's Institute for Astronomy, the system currently has four 0.5-meter telescopes. Two are located 160 km apart in the Hawaiian islands, at Haleakala (ATLAS-HKO, Observatory code T05) and Mauna Loa (ATLAS-MLO, Observatory code T08) observatories, one is located at the Sutherland Observatory (ATLAS–SAAO, Observatory code M22) in South Africa, and one is at the El Sauce Observatory in Rio Hurtado (Chile) (Observatory code W68).

ATLAS began observations in 2015 with one telescope at Haleakala, and a two-Hawaii-telescopes version became operational in 2017. The project then obtained NASA funding for two additional telescopes in the Southern hemisphere, which became operational in early 2022.^[1] Each telescope surveys one quarter of the whole observable sky four times per clear night,^[2] and the addition of the two southern telescopes improved ATLAS's four-fold coverage of the observable sky from every two clear nights to nightly, as well as filled its previous blind spot in the far southern sky.^[3]