A comet named Comet C/2023 A3 Tsuchinshan-Atlas, or A3, is nearing Earth after an 81,000-year journey and should be visible soon. Discovered last year, A3 is touted as the “comet of the decade” by the SETI Institute. It’s about 1,000 times rarer than Halley’s comet. Despite earlier concerns of it dimming, A3 is regaining brightness. NASA astronaut Don Petitt and others are tracking it. Viewing is best early morning on Sept. 27 and until Oct. 2, looking east-southeast about 75 minutes before sunrise.