There are currently over 5250 known comets, a number that is steadily increasing as more are discovered. Once a comet has been discovered, then its orbital path can be plotted as well as its expected return date determined. It is the study of astronomy and astrophysics which is the key to predicting the return of comets.

Roughly one comet per year is visible to the naked eye, though many of those are faint and unspectacular. Particularly bright examples are called Great Comets. Comets have been visited by unmanned probes such as the European Space Agency′s Rosetta, which became the first ever to land a robotic spacecraft on a comet, and NASA′s Deep Impact, which blasted a crater on Comet Tempel 1 to study its interior.

1P/Halleys, NPH: 28 July 2061

C/2021 S3 PanSTARRS, Not naked-eye

C/2023-A3, Comet Tsuchinshan-ATLAS. NPH: 27 Sept 2024. mag 6.1

13P/Olbers, NPH: 30 June 2024, mag 7, Not Naked-eyed

12P/Pons-Brooks, NPH: 21 April 2024. LPH: 22 May 1954. mag 5

144P/Kushida, LPH: 25 January 2024, mag 10 Not naked-eyed

62P/Tsuchinshan LPH: 25 December 2023, mag 8, Not naked eye, NPH: 2094

C-2020-F3 NEOWISE Comet

Great Comet Lovejoy, LPH: 16 December 2011; NPH: 2633 CE.; mag -4

Great Comet McNaught, LPH: 12 January 2007. NPH: non-p mag -5.5 Daylight

Great Comet Hyakutake, LPH: 01 May 1996; NPH: Unknown; mag 0

Hale-Bopp Comet

Comet Shoemaker-Levy 9, orbiting and then colliding with Jupiter in July 1994

1P-Halley, Halley′s Comet

Great Comet West, LPH: 25 February 1976. NPH: Unknown; mag -3

Great Comet Bennett, LPH: 20 March 1970. NPH: 3600 CE. mag 0

Great Comet Ikeya-Seki, LPH: 21 October 1965. NPH: 2760 CE. mag -10

Great Comet Seki-Lines, LPH: 1 April 1962; NPH:non-p; mag -2.5

Great Comet Arend-Roland, LPH: 08 April 1957; NPH: non-p; mag -1

Great Comet Mrkos, LPH: 01 August 1957; NPH: non-p; mag 1

Great Comet Skjellerup-Maristany

Great Halley′s Comet. Perihelion: 1910 CE, 1066 CE, 837 CE, 87 BCE, 12 BCE

C-1858 L1 (Great Donati), LPH: 30 Sept 1858. NPH: 3600 CE. Naked Eye Comet