Key Facts

Overview

Antoku is a large asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified Antoku as potentially hazardous because its orbit does not bring it close to Earth.

Antoku orbits the sun every 1,660 days (4.54 years), coming as close as 2.34 AU and reaching as far as 3.14 AU from the sun. Antoku is about 17.7 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of Philadelphia.

The rotation of Antoku has been observed. It completes a rotation on its axis every 6.73 hours.

Antoku's spectral type None (Tholen) / X (SMASSII) indicates that it is likely to contain iron, nickel, and cobalt.

No Close Approaches

Antoku's orbit is 1.34 AU from Earth's orbit at its closest point. This means that there is an extremely 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

Antoku's orbit is determined by observations dating back to Dec. 22, 1954. It was last officially observed on May 15, 2023. The IAU Minor Planet Center records 3,841 observations used to determine its orbit.

Accessibility and Exploration

This asteroid 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 Antoku:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.74 AU
  • Eccentricity: 0.1476
  • Inclination: 5.73°
  • Longitude of Ascending Node: 134.54°
  • Argument of Periapsis: 78.84°
  • Mean Anomaly: 328.63°

Physical Characteristics

  • Diameter: 17.74400 km
  • Magnitude: 12.57
  • Albedo: 0.059
  • Spectral type (SMASS): X

Derived Characteristics

  • Orbit Period: 1,660 days (4.54 years)
  • Avg. Orbit Speed: 17.96 km/s
  • Aphelion Distance: 3.14 AU
  • Perihelion Distance: 2.34 AU
  • Rotation Period: 6.73 hours
  • Approx. Composition: iron, nickel, and cobalt.

Map Comparison

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Orbit Simulation

Sky Map

The position of Antoku 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.