Key Facts


Orcus is a dwarf planet whose orbit extends beyond the orbit of Neptune. NASA JPL has not classified Orcus as potentially hazardous because its orbit does not bring it close to Earth.

Orcus orbits the sun every 89,600 days (245.31 years), coming as close as 30.28 AU and reaching as far as 48.06 AU from the sun. Based on its brightness and the way it reflects light, Orcus is probably between 965.061 to 2157.943 kilometers in diameter, making it the largest asteroid/dwarf planet, very roughly comparable in size to the U.S. state of Alaska.

The rotation of Orcus has been observed. It completes a rotation on its axis every 13.19 hours.

No Close Approaches

Orcus's orbit is 29.30 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

Orcus's orbit is determined by observations dating back to Nov. 8, 1951. It was last officially observed on May 25, 2020. The IAU Minor Planet Center records 1,006 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 Orcus:



   or view a random object

Orbital Elements

  • Epoch: 2459000.5 JD
  • Semi-major axis: 39.17 AU
  • Eccentricity: 0.227
  • Inclination: 20.59°
  • Longitude of Ascending Node: 268.8°
  • Argument of Periapsis: 72.31°
  • Mean Anomaly: 181.73°

Physical Characteristics

  • Diameter: ~1245.889 km
  • Magnitude: 2.2

Derived Characteristics

  • Orbit Period: 89,600 days (245.31 years)
  • Avg. Orbit Speed: 4.76 km/s
  • Aphelion Distance: 48.06 AU
  • Perihelion Distance: 30.28 AU
  • Rotation Period: 13.19 hours

Map Comparison

Click to load map

Orbit Simulation

Sky Map

The position of Orcus 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.