Key Facts


Thule is a large asteroid that orbits between Mars and Jupiter in the outer reaches of the main asteroid belt. NASA JPL has not classified Thule as potentially hazardous because its orbit does not bring it close to Earth.

Thule orbits the sun every 3,220 days (8.82 years), coming as close as 4.08 AU and reaching as far as 4.45 AU from the sun. Thule is about 126.6 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the U.S. state of Connecticut.

The rotation of Thule has been observed. It completes a rotation on its axis every 23.90 hours.

Thule's spectral type D (Tholen) / X (SMASSII) indicates that it is likely to contain iron, nickel, and cobalt.

No Close Approaches

Thule's orbit is 3.09 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

Thule's orbit is determined by observations dating back to Dec. 12, 1890. It was last officially observed on April 13, 2023. The IAU Minor Planet Center records 6,156 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 Thule:



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 4.264 AU
  • Eccentricity: 0.0439
  • Inclination: 2.33°
  • Longitude of Ascending Node: 71.88°
  • Argument of Periapsis: 27.69°
  • Mean Anomaly: 6.28°

Physical Characteristics

  • Diameter: 126.59000 km
  • Magnitude: 8.65
  • Albedo: 0.0412
  • Spectral type (Tholen): D
  • Spectral type (SMASS): X

Derived Characteristics

  • Orbit Period: 3,220 days (8.82 years)
  • Avg. Orbit Speed: 14.41 km/s
  • Aphelion Distance: 4.45 AU
  • Perihelion Distance: 4.08 AU
  • Rotation Period: 23.90 hours
  • Approx. Composition: iron, nickel, and cobalt.

Map Comparison

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Orbit Simulation

Sky Map

The position of Thule 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.