Key Facts


Ocllo is a large asteroid with an orbit that crosses the orbit of Mars. NASA JPL has not classified Ocllo as potentially hazardous because its orbit does not bring it close to Earth.

Ocllo orbits the sun every 1,530 days (4.19 years), coming as close as 1.61 AU and reaching as far as 3.58 AU from the sun. Ocllo is about 17.8 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of Philadelphia.

The rotation of Ocllo has been observed. It completes a rotation on its axis every 7.32 hours.

No Close Approaches

Ocllo's orbit is 0.67 AU from Earth's orbit at its closest point. This means that there is a very 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

Ocllo's orbit is determined by observations dating back to Nov. 20, 1914. It was last officially observed on Dec. 29, 2022. The IAU Minor Planet Center records 5,982 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 Ocllo:



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.593 AU
  • Eccentricity: 0.3795
  • Inclination: 18.95°
  • Longitude of Ascending Node: 34.4°
  • Argument of Periapsis: 305.92°
  • Mean Anomaly: 66.75°

Physical Characteristics

  • Diameter: 17.83000 km
  • Magnitude: 11.61
  • Albedo: 0.057
  • Spectral type (Tholen): X

Derived Characteristics

  • Orbit Period: 1,530 days (4.19 years)
  • Avg. Orbit Speed: 18.44 km/s
  • Aphelion Distance: 3.58 AU
  • Perihelion Distance: 1.61 AU
  • Rotation Period: 7.32 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of Ocllo 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.