Key Facts

  • Categorized as a Halley-type Comet
  • Comparable in size to the city of Boston (11.00 km diameter)
  • Will pass within 13,701,439 km of Earth in 2134
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation


1P/Halley is a large comet with a medium-length orbit that is highly inclined to the ecliptic plane of the solar system. NASA JPL has classified 1P/Halley as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.

1P/Halley orbits the sun every 27,500 days (75.29 years), coming as close as 0.59 AU and reaching as far as 35.07 AU from the sun. Its orbit is highly elliptical. 1P/Halley is about 11.0 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of Boston.

Close Approaches

1P/Halley's orbit is 0.06 AU from Earth's orbit at its closest point. This means that there is an wide berth between this asteroid and Earth at all times.

1P/Halley has 1 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
May 7, 2134 13,701,439 65.280

Images and Observations

1P/Halley's orbit is determined by observations dating back to Aug. 21, 1835. It was last officially observed on Jan. 11, 1994. The IAU Minor Planet Center records 7,428 observations used to determine its orbit.

Accessibility and Exploration

This comet is not considered a viable target for human exploration by the NHATS study.

Similar Objects

These objects have orbits that share similar characteristics to the orbit of 1P/Halley:



   or view a random object

Orbital Elements

  • Epoch: 2449400.5 JD
  • Semi-major axis: 17.83 AU
  • Eccentricity: 0.9671
  • Inclination: 162.26°
  • Longitude of Ascending Node: 58.42°
  • Argument of Periapsis: 111.33°
  • Mean Anomaly: 38.38°

Physical Characteristics

  • Diameter: 11.00000 km
  • Magnitude: 5.5
  • Albedo: 0.04

Derived Characteristics

  • Orbit Period: 27,500 days (75.29 years)
  • Avg. Orbit Speed: 7.05 km/s
  • Aphelion Distance: 35.07 AU
  • Perihelion Distance: 0.59 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 1P/Halley is indicated by a ◯ pink circle. Note that the object may not be in your current field of view. Use the controls below to adjust position, location, and time.