|Discovered by||Francesco de Vico|
|Discovery date||20 February 1846|
|1846 IV, P/1846 D1, P/1995 S1|
|Orbital characteristics A|
|Semi-major axis||17.6808 AU|
|Orbital period||74.35 yr|
|Last perihelion||October 6, 1995|
|Next perihelion||14 October 2069|
21 October 2069
122P/de Vico (provisional designation: 1846 D1) is a periodic comet with an orbital period of 74 years. It fits the classical definition of a Halley-type comet with (20 years < period < 200 years). It was discovered by Francesco de Vico in Rome on February 20, 1846.
Daniel Kirkwood in 1884 noticed that the comet shares elements with comet 12P/Pons-Brooks. He suggested that 122P had calved off Pons-Brooks some centuries prior. Later he identified the two comets' capture into their elliptical orbits (or their parent body's capture) with their shared aphelion close to Neptune 991 CE.