This comet, designated 12P/Pons-Brooks is a periodic comet with an orbital period of 71 years. ¹ 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 discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and then, on its next appearance in 1883 by William Robert Brooks. There are some ancient records of comets that could have been 12P/Pons–Brooks.

The next perihelion passage has been calculated to be on 21 April 2024 with its closest approach to Earth occurring on 02 June 2024 at a distance of about 144.16 million miles (232 million km or 1.5 AU), with the maximum brightness of magnitude 4.5, making it visible with the naked eye.

12 July 1812 by Jean-Louis Pons

Independently, this comet was found by Vincent Wisniewski on 01 August, and Alexis Bouvard on 02 August of the same year. Then, on 13 August 1812, the comet was spotted with the naked eye and by the end of the month a tail measuring 2 degrees in length was reported.

02 September 1883 by William Robert Brooks

Then, on 20 November 1883, the comet became visible with naked eye and brightened to a magnitude of 3 with occasional outbursts.

A comet that was observed by Paolo dal Pozzo Toscanelli in January 1457 (and mentioned in Chinese documents) has been identified as comet 12P/Pons–Brooks.

A comet that was observed in 1385 and recorded by the Chinese in Ming Shilu has been identified as 12P/Pons-Brooks. The apparition of the comet during this perihelion was very favorable, one which was also mentioned in some European records. In both the above apparitions the comet had a magnitude of 3 or brighter.

It is also possible that it was also a comet that has been included in Chinese records during September 245 CE.

On 20 July 2023, 12P/Pons-Brooks comet underwent an outburst when it was 3.9 AU from the Sun. This resulted in the comet having a horseshoe shaped coma, most likely created by the release of billions of pounds of dust and ice into space. The comet outburst again on 05 August 2023, then again on 05 October 2023 increasing its magnitude both times.

The comet outburst again on 01 November, 14 November, 14 December and 18 January 2024. By the middle of February, the comet brightness was at 7.5 magnitude and developed an ion tail of about two degrees long. Then, by 07 March, 2024, the comet brightness was at 5.5 magnitude and has moved to within 10 degrees of the Andromeda Galaxy.

The perihelion passage is on 21 April 2024 at 0.781 AU from the Sun with a velocity of 47 km/s. The Closest Approach to Earth will be 42 days later on 02 June 2024 when the comet will be 1.55 AU from the Earh. Maximum apparent brightness is expected to be at 4.5 magnutide.