Comet P1 Nishimura was discovered by a Japanese amateur astronomer, Hideo Nishimura. This is the third comet that bears his name! He also discovered C/1994 N1 (Nakamura-Nishimura-Machholz) and C/2021 O1 (Nishimura). He also discovered a nova, V6596 Sagittari. Mr. Nishimura discovered the comet in images he obtained with a Canon EOS 6D camera using 200-mm f/3 telephoto lens. He initially identified the comet on August 12, 2023, but found that he had also taken its image the previous night.
Comet Nishimura is now known to be a periodic comet (hence the "P" in its name.) Its last visit to the inner solar system was 433 years ago. The comet also showed up in the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) in January 2023, but was not identified before Nishimura's discovery.
This image of C/2023 P1 (Nishimura) was downloaded from Creative Commons. It was taken on August 25, 2023 at ~6:20 (UTC+2)from Trevinca-Skies on Spain. The field of view is 43.2' x 43.2'.
As September opens, the comet has joined the planet Venus in the constellation of Cancer. It is racing through the inner solar system on its way to perihelion on September 17, 2023. After perihelion, it may be much brighter, but will be speeding its way back to the outer solar system. At that time, observers will pick it up in the evening sky, rather than the morning sky, but it will still be close to the horizon and the Sun. It has been noted that the Nishimura comet may be the cause of the Sigma-Hydrid meteor shower that occurs annually in December.
Comet C2023 E1 Atlas is a long period comet that was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on March 1, 2023. The comet's perihelion was July 1, 2023. The comet's closest approach to Earth was August 18 passing at a distance of 0.375 AU.
ATLAS is a robotic astronomical survey and early warning system funded by NASA. It is meant to detect small near-Earth objects a few weeks to days before they impact Earth. Comet ATLAS was featured on Astronomy Picture of the Day (APOD) on July 14, 2023.
Recent Comet Brightness Estimates - reported to the Minor Planet Center at Harvard. Check here to see what comet observations have been made and submitted to the Center. Magnitude estimates are made by the astronomers and are subjective unless otherwise stated.
Rosetta Mission - Comet Exploration Mission (Mars Swing by Feb. 25, 2007.) Arrived at comet 67P/Churyumov-Gerasimenko on November 12, 2016. It deployed its probe, Philae, to the surface of the comet. Rosetta followed the periodic comet through perihelion on Aug. 13, 2015. On Sept. 30, 2016, the Rosetta spacecraft performed a controlled crash on 67P/Churyumov-Gerasimenko to end its mission.
C/2022 E3 (ZTF) - It is a long period comet that was discovered by the Zwicky Transient Facility on March 2, 2022. Perihelion occured on January 12, 2023 but its closest approach to Earth (0.29 AU or 42 million km) came on the outbound leg of E3's visit on February 1. This comet returns to the inner solar system every 50,000 years. The coma is very green and the tail wass quite long. The image featured here was taken by Lorenzo Busilacchi using a C-11 telescope and retreived from Flickr on January 17, 2023.
The green coma of C/2022 E3 (ZTF) is caused by the breaking down of diatom carbons. Anton explains in depth and very well.
For many astronomers, predicting whether or not a comet will be very bright is a tough challenge. In 2020, Comet C/2020 F3 took astronomers by surprise when it brightened up tremendously after its perihelion visit to the Sun. This sleeper was discovered on March 27, 2020 by the NEOWISE space telescope.
The comet was a 16-mag object when discovered. It was 2.1 au from the Sun at that time. It brightened quickly and reached 10th magnitude by the end of April. Perihelion was on July 3 and it will be 0.69 au at its closest approach to Earth around July 22.
The image below was created by Tom Ruen and licensed under
CC BY-SA 4.0 and can be found on Wikipedia for more information. The bright yellow line in the diagram represents the ecliptic.
Comet Lovejoy (C/2014 Q2)
At last, an exciting comet that wasn't overbilled in the media. This comet was the fifth comet discovered by comet hunter Terry Lovejoy. Using CCD camera images taken with a Celestron C-8 telescope, Lovejoy found this comet from Queensland, Australia on August 17, 2014. A long period comet, the perihelion date for Comet Lovejoy was January 30, 2015. Closest approach to Earth was January 7 when it was 43.6 million miles or 70.2 million km away from us. It reached 4th magnitude within the limits for observing with the unaided eye.
Comet C/2012 S1 (ISON) was sun grazing comet was discovered on September 21, 2012 by Artyom Novichonok and Vitali Nevski, using a 16-inch telescope that is part of the International Scientific Optical Network (ISON). It was nicknamed the Holiday comet because its perihelion date was November 28, Thanksgiving Day in the U.S. Despite high expectations, this comet broke apart due to its close encounter with the Sun. After a long life of 4.5 billion years, ISON was destroyed at perihelion.
The brightest comet of the new millennium so far! C/2006 P1 a.k.a. Comet McNaught. Discovered by Robert McNaught of the Siding Spring Observatory in Australia on August 7, 2006. Perihelion was January 12, 2007. Peak magnitude estimate -0.6! This comet will be long remembered for its magnificent tail.
So long, Comet McNaught, it won't be back to visit the inner solar system again.
In 1995, Comet 73P/Schwassmann-Wachmann 3 split into "mini-comets" flying single file through space, much like Shoemaker/Levy9 that crashed into Jupiter. Closest approach to Earth: 5 million miles on May 15, 2006.