Comet · 1P

1P/Halley

A comet visited by an international fleet

Giotto, the Vega probes and Japanese spacecraft investigated Halley during its 1986 passage. Halley’s nucleus is visible in Giotto’s close-encounter images.

1P/Halley · spacecraft or telescope observation — Spacecraft or telescope observation; colour and processing follow the linked source. Halley Multicolor Camera Team / Giotto Project / ESA · Image source ↗

Understand this world

From a nucleus to a coma and tailsFollow energy and material from an irregular comet nucleus into its surrounding gas and dust, using Rosetta’s observations of 67P. · 3 min

Measurements

Effective diameter: 11 km
Semimajor axis: 17.929 AU
Orbital period: 27,728.046 Earth days

Orbit, physical values and uncertainties

eccentricity: .9679359956953211 ± 7.5527E-9
semi-major axis: 17.92863504856923 au ± 9.9587E-9
perihelion distance: .5748638313743413 au ± 1.3552E-7
inclination; angle with respect to x-y ecliptic plane: 162.1905300439129 deg ± 1.5093E-5
longitude of the ascending node: 59.09894720612437 deg ± 1.9861E-5
argument of perihelion: 112.2414314637764 deg ± 2.0534E-5
mean anomaly: 274.3823371366792 deg ± 1.2457E-7
time of perihelion passage: 2446469.973616146677 TDB ± 1.2976E-5
sidereal orbital period: 27728.04608790421 d ± 2.3103E-5
mean motion: .01298324443268444 deg/d ± 1.0818E-11
aphelion distance: 35.28240626576412 au ± 1.9598E-8
comet total magnitude: 5.5
comet total magnitude slope: 8.0
comet nuclear magnitude: 13.6
comet nuclear magnitude slope: 5.0
comet nuclear phase coefficient: 0.03
diameter: 11.0 km
extent: 14.9x8.2 km
geometric albedo: 0.04 ± 0.01

Published JPL orbital elements describe their stated epoch; they are not current positions. Small-body diameters can be effective/model-dependent sizes, not spherical shapes. Missing measurements remain unavailable. Pluto’s diameter uses the New Horizons reference rather than an empty SBDB field. Orbital epoch: JD 2439875.5 TDB.

Object reference ↗

Missions & milestones

5 launches · 0 connected events

These are target-related flights and every connected programme record in the production catalogue. A connected event may concern another stage or target of the same journey. Launch outcome does not establish arrival or current operation.

TARGET-RELATED FLIGHT