Comet Encke

2P/Encke
Comet Encke
Discovery
Discovered byPierre Méchain;
Johann Franz Encke (recognition of periodicity)
Discovery date17 January 1786[1]
Designations
1786 I; 1795; 1805;
1819 I; 1822 II; 1825 III;
1829; 1832 I; 1835 II;
1838; 1842 I; 1845 IV
Orbital characteristics
Epoch2023 September 13[1]
Aphelion4.098 AU
Perihelion0.33960 AU
Semi-major axis2.2187 AU
Eccentricity0.8469
Orbital period3.30 yr
3y 3m 27d (perihelion to perihelion)
Max. orbital speed69.5 km/s (250,000 km/h)[2]
Inclination11.34°
Argument of
periapsis		187.3°
Last perihelion22 October 2023[2]
Next perihelion9 February 2027[citation needed]
TJupiter3.025[1]
Earth MOID0.17 AU (25 million km)[1]
Physical characteristics
Dimensions4.8 km[1]

Comet Encke /ˈɛŋki/, or Encke's Comet (official designation: 2P/Encke), is a periodic comet that completes an orbit of the Sun once every 3.3 years. (This is the shortest period of a reasonably bright comet; the faint main-belt comet 311P/PanSTARRS has a period of 3.2 years.) Encke was first recorded by Pierre Méchain on 17 January 1786,[3] but it was not recognized as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke. Like Halley's Comet, it is unusual in its being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light its nucleus receives, although comets generate a large coma and tail that can make them much more visible during their perihelion (closest approach to the Sun). The diameter of the nucleus of Encke's Comet is 4.8 km.[1]

  1. ^ a b c d e f Cite error: The named reference jpldata was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Horizons2023 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Marsden was invoked but never defined (see the help page).