Comet C/2023 A3, a non-periodic comet with an estimated orbital period of 80,000 years, reached its peak brightness of magnitude -4.9 on October 9, 2023. This made it one of the brightest comets in the last century. Discovered by the Purple Mountain Observatory in January 2023 and confirmed by the ATLAS Observatory in February, it was initially predicted to disintegrate as it approached perihelion, the closest point to the sun, on September 27. Contrary to expectations, it did not break apart.
After coming within approximately 70 million kilometers of Earth on October 12, C/2023 A3 remained visible to the naked eye for several days in the evening sky, although it began to dim post-closest approach. As the comet continues its journey back to the outer solar system, observers noted its diminishing brightness.
In a related event, comet C/2024 S1, part of the Kreutz sungrazers, disintegrated completely during its perihelion passage on October 28, 2023. These comets are notorious for their high risk of disintegration due to their close approach to the sun.
In other news, Voyager 1, now over 24 billion kilometers from Earth, successfully switched to a backup S-band antenna after communication issues with its primary transmitter. This marks the first use of the backup since 1981, as the spacecraft's autonomous fault-protection system had turned off the main X-band radio transmitter.