Key Facts


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

Clifford orbits the sun every 1,040 days (2.85 years), coming as close as 1.60 AU and reaching as far as 2.42 AU from the sun. Clifford is about 4.7 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the San Francisco Bay.

The rotation of Clifford has been observed. It completes a rotation on its axis every 3.24 hours.

Clifford's spectral type None (Tholen) / Cb (SMASSII) indicates that it is likely to contain water, iron, nickel, cobalt, nitrogen, and ammonia.

No Close Approaches

Clifford's orbit is 0.62 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

Clifford's orbit is determined by observations dating back to Oct. 5, 1981. It was last officially observed on June 25, 2022. The IAU Minor Planet Center records 2,120 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 Clifford:



   or view a random object

Orbital Elements

  • Epoch: 2459800.5 JD
  • Semi-major axis: 2.01 AU
  • Eccentricity: 0.2034
  • Inclination: 21.02°
  • Longitude of Ascending Node: 76.84°
  • Argument of Periapsis: 3.69°
  • Mean Anomaly: 89.2°

Physical Characteristics

  • Diameter: 4.70800 km
  • Magnitude: 14.68
  • Albedo: 0.087
  • Spectral type (SMASS): Cb

Derived Characteristics

  • Orbit Period: 1,040 days (2.85 years)
  • Avg. Orbit Speed: 21.03 km/s
  • Aphelion Distance: 2.42 AU
  • Perihelion Distance: 1.60 AU
  • Rotation Period: 3.24 hours
  • Approx. Composition: water, iron, nickel, cobalt, nitrogen, and ammonia.

Map Comparison

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Orbit Simulation

Sky Map

The position of Clifford 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.

Size Rendering

The above comparison is an artistic rendering that uses available data on the diameter of Clifford to create an approximate landscape rendering with Mount Everest in the background. This approximation is built for full-resolution desktop browsers. Shape, color, and texture of asteroid are imagined.