If it was not a Great Comet, it was at least a very, very good one. Formally known as C/2023 A3, this ice ball from the outer solar system was first discovered in images taken Jan. 9, 2023 ...

The likes of comet F3 NEOWISE in 2020 and last year’s comet A3 Tsuchinshan-ATLAS aside, most have been rather dim. Cue C/2025 F2 (SWAN), which was discovered in late March. Briefly visible to ...