Key Facts


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

Sylvia orbits the sun every 2,370 days (6.49 years), coming as close as 3.15 AU and reaching as far as 3.80 AU from the sun. Sylvia is about 253.1 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the U.S. state of West Virginia.

The rotation of Sylvia has been observed. It completes a rotation on its axis every 5.18 hours.

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

No Close Approaches

Sylvia's orbit is 2.17 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

Sylvia's orbit is determined by observations dating back to May 5, 1885. It was last officially observed on June 17, 2023. The IAU Minor Planet Center records 5,540 observations used to determine its orbit.

Scientists have been able to determine this object's shape:

View asteroid Sylvia in 3D.

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 Sylvia:



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 3.477 AU
  • Eccentricity: 0.0939
  • Inclination: 10.88°
  • Longitude of Ascending Node: 73.01°
  • Argument of Periapsis: 264.4°
  • Mean Anomaly: 334.82°

Physical Characteristics

  • Diameter: 253.05100 km
  • Magnitude: 6.97
  • Albedo: 0.046
  • Spectral type (Tholen): P
  • Spectral type (SMASS): X

Derived Characteristics

  • Orbit Period: 2,370 days (6.49 years)
  • Avg. Orbit Speed: 15.96 km/s
  • Aphelion Distance: 3.80 AU
  • Perihelion Distance: 3.15 AU
  • Rotation Period: 5.18 hours
  • Approx. Composition: iron, nickel, and cobalt.

Map Comparison

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Orbit Simulation

Sky Map

The position of Sylvia 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.