Key Facts

Overview

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

Okayama orbits the sun every 1,350 days (3.70 years), coming as close as 2.15 AU and reaching as far as 2.64 AU from the sun. Okayama is about 18.1 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of Philadelphia.

The rotation of Okayama has been observed. It completes a rotation on its axis every 4.55 hours.

No Close Approaches

Okayama's orbit is 1.16 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

Okayama's orbit is determined by observations dating back to Jan. 13, 1931. It was last officially observed on Feb. 3, 2023. The IAU Minor Planet Center records 4,136 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 Okayama:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.395 AU
  • Eccentricity: 0.1028
  • Inclination: 4.84°
  • Longitude of Ascending Node: 148.93°
  • Argument of Periapsis: 247.87°
  • Mean Anomaly: 55.86°

Physical Characteristics

  • Diameter: 18.07900 km
  • Magnitude: 12.38
  • Albedo: 0.083

Derived Characteristics

  • Orbit Period: 1,350 days (3.70 years)
  • Avg. Orbit Speed: 19.30 km/s
  • Aphelion Distance: 2.64 AU
  • Perihelion Distance: 2.15 AU
  • Rotation Period: 4.55 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of Okayama 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.