Key Facts


153P/Ikeya-Zhang is a large comet whose orbit does not match any defined comet orbit class. NASA JPL has not classified 153P/Ikeya-Zhang as potentially hazardous because its orbit does not bring it close to Earth.

153P/Ikeya-Zhang orbits the sun every 133,000 days (364.13 years), coming as close as 0.51 AU and reaching as far as 101.73 AU from the sun. Its orbit is highly elliptical. Based on its brightness and the way it reflects light, 153P/Ikeya-Zhang is probably between 2658.000 to 5943.469 kilometers in diameter, making it the largest asteroid/dwarf planet, very roughly comparable in size to the U.S. state of Alaska.

No Close Approaches

153P/Ikeya-Zhang's orbit is 0.33 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.

Orbital simulations conducted by NASA JPL's CNEOS do not show any close approaches to Earth.

Images and Observations

153P/Ikeya-Zhang's orbit is determined by observations dating back to Aug. 25, 2001. It was last officially observed on Oct. 2, 2002. The IAU Minor Planet Center records 1,893 observations used to determine its orbit.

Accessibility and Exploration

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



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Orbital Elements

  • Epoch: 2452402.5 JD
  • Semi-major axis: 51.12 AU
  • Eccentricity: 0.9901
  • Inclination: 28.12°
  • Longitude of Ascending Node: 93.37°
  • Argument of Periapsis: 34.67°
  • Mean Anomaly: 0.13°

Physical Characteristics

  • Diameter: ~3431.463 km
  • Magnitude: 4.0

Derived Characteristics

  • Orbit Period: 133,000 days (364.13 years)
  • Avg. Orbit Speed: 4.18 km/s
  • Aphelion Distance: 101.73 AU
  • Perihelion Distance: 0.51 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 153P/Ikeya-Zhang 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.