12P/Pons–Brooks is a periodic comet with an orbital period of 71 years. Comets with an orbital period of 20–200 years are referred to as Halley-type comets. It is one of the brightest known periodic comets, reaching an absolute visual magnitude of about 5 in its approach to perihelion. Comet Pons-Brooks was conclusively discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and on its next appearance in 1883 by William Robert Brooks. There are ancient records of comets that are suspected of having been apparitions of 12P/Pons–Brooks.The next perihelion passage is 21 April 2024, with closest approach to Earth being 1.55 AU (232 million km) on 2 June 2024. The comet is expected to brighten to about apparent magnitude 4.5. The comet nucleus is estimated to be around 30 km in diameter, assuming it was not producing too much dust and gas during the 2020 photometric measurements.

Comet C/2023 A3 (Tsuchinshan-ATLAS) is a long-period comet discovered in January 2023 by two independent surveys: the Purple Mountain Observatory in China (Tsuchinshan) and the Asteroid Terrestrial-impact Last Alert System (ATLAS). It's expected to reach its closest approach to the Sun (perihelion) in September 2024, and if it survives, it could become a bright object visible to the naked eye, potentially reaching its brightest in October 2024. Comet C/2023 A3 is notable for its rapid approach, and early observations suggest it might put on an impressive display as it moves through the inner solar system.