In 2023, a whole bunch of comets will reach perihelion and gain maximum brightness. Some of them will likely become visible through small telescopes and binoculars or even with the naked eye. In our list, we included ten comets that are expected to reach a magnitude of 10 or brighter. All of them can be easily found in the sky with the help of our Sky Tonight app — we’ll tell you how at the end of this article.
C/2017 K2 (PanSTARRS)
- Perihelion: December 19, 2022 (mag 8.3)
- Closest approach to Earth: July 14, 2022 (mag 8.7)
- Where to observe: Southern Hemisphere
- Visibility forecast: Although the comet comes nearest to the Sun at the end of 2022, it might get brighter at the beginning of 2023 and even reach a magnitude of 6. Try observing the comet in mid-January 2023 with a small telescope or large binoculars.
- Description: C/2017 K2 (PanSTARRS) is a long-period comet with a hyperbolic orbit that came from the Oort cloud. It was discovered on May 21, 2017, by the Pan-STARRS 1 telescope at Haleakala Observatory, Hawaii, USA. This comet has such a long orbital period that next time it will return to the inner Solar System only in the year 20000!
C/2022 E3 (ZTF) ⭐
- Perihelion: January 12 (mag 6.5)
- Closest approach to Earth: February 1 (mag 4.7)
- Where to observe: The comet is best observed from the Northern Hemisphere. In the Southern Hemisphere, it’s not observable until early February.
- Visibility forecast: This comet has the potential to become one of the brightest of the year. The best observation conditions will be at the end of January — between perihelion and closest approach. At that time, the Moon will be near its new phase and won’t hinder your observations. The comet is also expected to gain maximum tail length around this time. C/2022 E3 (ZTF) will likely be visible through binoculars and maybe even with the naked eye! On February 12, you will also have a chance to observe the fading comet pass near zero-magnitude Mars.
- Description: C/2022 E3 (ZTF) is a long-period comet discovered on March 2, 2022, by the Zwicky Transient Facility in the USA. It was initially considered to be an asteroid, but later a very condensed coma was revealed, indicating that the object was a comet.
You can find out more about Comet C/2022 E3 (ZTF) in our dedicated article.
96P/Machholz
- Perihelion: January 31 (mag 0.7)
- Closest approach to Earth: January 31 (mag 0.7)
- Where to observe: Both hemispheres
- Visibility forecast: Unfortunately, at the moment of maximum brightness, the comet will be positioned too close to the Sun in the sky and won’t be visible. Observers near the equator will have a potential chance to see 96P/Machholz in late February. However, by this time, the comet will have already faded to 10th magnitude.
- Description: 96P/Machholz is a short-period comet discovered on May 12, 1986, by amateur astronomer Donald Machholz. It is a [sungrazing comet](https://svs.gsfc.nasa.gov/11307), which means it passes extremely close to the Sun’s surface at perihelion. 96P/Machholz also has a unique chemical composition that implies possible extrasolar origin.
C/2020 V2 (ZTF)
- Perihelion: May 8 (mag 10.0)
- Closest approach to Earth: September 17 (mag 9.6)
- Where to observe: Both hemispheres
- Visibility forecast: At perihelion, the comet will be positioned too close to the Sun in the sky and won’t be visible. However, you can observe it at the moment of the closest approach in September — it will be brighter and well-positioned for observations. C/2020 V2 (ZTF) might be visible in small telescopes.
- Description: C/2020 V2 (ZTF) is a long-period comet discovered on November 2, 2020, by the Zwicky Transient Facility in the USA.
C/2021 T4 (Lemmon)
- Perihelion: July 31 (mag 8.2)
- Closest approach to Earth: July 20 (mag 7.8)
- Where to observe: Southern Hemisphere
- Visibility forecast: The comet will be positioned high in the sky in the southern latitudes. It might become visible in small telescopes or large binoculars.
- Description: C/2021 T4 (Lemmon) is a long-period comet discovered on October 7, 2021, by the Mount Lemmon Observatory in the USA.
103P/Hartley
- Perihelion: October 12 (mag 8.4)
- Closest approach to Earth: September 26 (mag 8.3)
- Where to observe: Both hemispheres
- Visibility forecast: At perihelion, the comet will be well-placed in the sky for the observers from the Northern Hemisphere. In the Southern Hemisphere, it will be positioned much lower but will still be observable. It might become visible through small telescopes or large binoculars already at the end of September.
- Description: 103P/Hartley is a small short-period comet discovered by Malcolm Hartley in 1986 at the Siding Spring Observatory, Australia. On November 4, 2010, the comet was visited by NASA’s Deep Impact spacecraft — it came within 700 km of the comet and returned detailed photographs of its peanut-shaped nucleus.
2P/Encke
- Perihelion: October 21 (mag 6.9)
- Closest approach to Earth: September 24 (mag 9.9)
- Where to observe: Northern Hemisphere
- Visibility forecast: At its greatest brightness in October, 2P/Encke will only be visible in the morning sky just before sunrise. It’s not expected to be visible to the naked eye but might become observable through binoculars.
- Description: 2P/Encke has the shortest orbital period of any known comet — about 3.3 years. This comet was first observed by French astronomer Pierre Méchain on January 17, 1786, but got its name after German astronomer Johann Franz Encke, who calculated its orbit in 1819.
62P/Tsuchinshan
- Perihelion: December 24 (mag 7.1)
- Closest approach to Earth: January 30, 2024 (mag 7.6)
- Where to observe: Northern Hemisphere
- Visibility forecast: At perihelion, the comet will be well-positioned in the sky for observations. It might become bright enough to be observable through binoculars.
- Description: 62P/Tsuchinshan is a short-period comet discovered on January 1, 1965, at Purple Mountain Observatory (Zijinshan Astronomical Observatory) in Nanking, China. Its orbital period (6.4 years) is relatively short compared to other comets.
144P/Kushida
- Perihelion: January 25, 2024 (mag 7.3)
- Closest approach to Earth: December 12 (mag 7.5)
- Where to observe: Both hemispheres
- Visibility forecast: Although the comet reaches its maximum brightness only in 2024, it will become observable with large binoculars and small telescopes by the end of 2023.
- Description: 144P/Kushida is a short-period comet discovered on January 8, 1994, by Yoshio Kushida at the Yatsugatake South Base Observatory in Japan. Its orbital period (7.6 years) is quite short compared to other comets.
C/2021 S3 (PanSTARRS)
- Perihelion: February 14, 2024 (mag 7.3)
- Closest approach to Earth: March 14, 2024 (mag 7.3)
- Where to observe: Southern Hemisphere (before perihelion), Northern Hemisphere (after perihelion)
- Visibility forecast: Although the comet reaches perihelion only in 2024, it might brighten to magnitude 9 by the end of 2023. In this case, it might become observable with small telescopes.
- Description: C/2021 S3 (PanSTARRS) is a short-period comet discovered on September 24, 2021, by the Pan-STARRS 2 telescope at Haleakala Observatory, Hawaii, USA.
How to find a comet using Sky Tonight?
Comets are faint and fuzzy objects that are hard to detect, so it’s best to know their location for certain. The Sky Tonight app will help you quickly find any bright comet in the sky. Here’s what you need to do:
- Tap the magnifier icon at the lower part of the screen;
- In the Search field, enter the comet’s name (for instance, “2022 E3 (ZTF)”);
- Find the comet in the search results and tap the blue target icon next to its name;
- The app will show the comet’s current location in the sky;
- Point your device at the sky and follow the white arrow to find the comet.
You can also tap the comet’s name in the search results and then go to the Events tab to view the events related to the comet: perihelion and closest approach to Earth. Tap the blue target icon next to the event to see the comet’s location at the time of perihelion or closest approach.
Bottom line: In 2023, there will be at least ten comets that can potentially reach a magnitude of 10 or brighter. Some of these comets might become visible through binoculars or even with the naked eye. Let’s keep our fingers crossed!
While working on this article, we used data provided by the Institute of Astronomy (Cambridge), comet observers Seiichi Yoshida and Gideon van Buitenen, as well as the In-The-Sky website. These sources have differing predictions regarding the comets’ brightness, so we picked the most “optimistic” numbers for our list.
