by Brian Lin (’27) | February 2, 2024

This year, multiple comets, many of which take multiple decades to orbit, reach their point closest to Earth. Even more exciting is that these comets will be visible with binoculars, and even to the naked eye.

On December 25, 2023, the comet 62P/Tsuchinshan reached its perihelion, a comet’s closest point to the sun. 62P/Tsuchinshan was discovered in January of 1965 in Nanking, China and has a relatively short orbital period of 6.4 years. On January 29, it reached its maximum visual magnitude—the measurement of a comet’s brightness—of 9.5. For reference, the sun has a magnitude of -27, a full moon has a magnitude of -13, and Pluto has a magnitude of 16. Brightness predictions of comets change frequently, and are based on multiple factors, including size and rate of shedding cloudy material. 

First found in 1994 at the Yatsugatake Observatory in Japan, the comet 144P/Kushida reached its perihelion on January 25 with a visual magnitude of 8.5. 144P/Kushida has a relatively short orbit time (7.6 years) in comparison to other comets mentioned.

With an orbital period of 71 years, the comet 12P/Pons-Brooks reaches its perihelion on April 21 and will have a visual magnitude of 4.2. The comet is named after Jean-Louis Pons and William Robert Brooks; Jean-Louis Pons first discovered the comet in 1812, and William Robert Brooks later spotted it in 1883. It will be closest to Earth in June and will be visible to the naked eye if there is a clear and dark sky.

Between June 30 and July 20, the comet 13P/Olbers will reach a magnitude of around 7.5. It was discovered by Heinrich Olbers in 1815 and completes an orbit every 69 years.

Recently discovered by the Purple Mountain Observatory on January 9, 2023, C/2023 A3 (Tsuchinshan-ATLAS) reaches its perihelion with a magnitude of 0.2 on September 27. It will be brightest on October 12 with a magnitude of -0.9.

Lastly, The comet 3330/LINEAR will reach its perihelion on November 29 and will have a magnitude of 10. It was discovered by the LINEAR project, which also discovered numerous other comets in 2007. It completes an orbit every 8.7 years.

Many comets that are only visible every few decades can be seen this year. Some have been established for decades, and some are being seen for the first time. Next time you are outdoors and look up to see a clear sky filled with stars, one of these comets may be up there, too.