AI overview
A halo is a ring of light that appears around the sun or moon when sunlight or moonlight passes through ice crystals in the atmosphere. It matters because it's a beautiful natural phenomenon that has inspired art and folklore for centuries, and it can also indicate changing weather patterns since the ice crystals that create halos often precede rain or snow.
AI-generated from the Wikipedia summary — may contain errors.
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A 22° halo around the Sun, observed over Bretton Woods, New Hampshire, USA on February 13, 2021 A 22° halo and circumscribed halo around the Moon, observed near Kitt Peak National Observatory From top to bottom:A circumzenithal arc, supralateral arc, Parry arc, upper tangent arc, and 22° halo
A halo (from Ancient Greek ἅλως (hálōs) 'threshing floor, disk') is an optical phenomenon produced by light (typically from the Sun or Moon) interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Many of these appear near the Sun or Moon, but others occur elsewhere or even in the opposite part of the sky. Among the best known halo types are the circular halo (properly called the 22° halo), light pillars, and sun dogs, but many others occur; some are fairly common while others are extremely rare.