Key Facts


Comet 38P/Stephan-Oterma is an object with a medium-length orbit that is highly inclined to the ecliptic plane of the solar system. NASA JPL has not classified 38P/Stephan-Oterma as potentially hazardous because its orbit does not bring it close to Earth.

38P/Stephan-Oterma orbits the sun every 13,900 days (38.06 years), coming as close as 1.59 AU and reaching as far as 20.99 AU from the sun. Its orbit is highly elliptical.

No Close Approaches

38P/Stephan-Oterma's orbit is 0.60 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

38P/Stephan-Oterma's orbit is determined by observations dating back to Nov. 6, 1942. It was last officially observed on May 21, 2020. The IAU Minor Planet Center records 3,265 observations used to determine its orbit.

Accessibility and Exploration

This comet 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 38P/Stephan-Oterma:



   or view a random object

Orbital Elements

  • Epoch: 2458262.5 JD
  • Semi-major axis: 11.29 AU
  • Eccentricity: 0.8593
  • Inclination: 18.35°
  • Longitude of Ascending Node: 78.0°
  • Argument of Periapsis: 359.59°
  • Mean Anomaly: 355.56°

Physical Characteristics

  • Magnitude: 11.5

Derived Characteristics

  • Orbit Period: 13,900 days (38.06 years)
  • Avg. Orbit Speed: 8.84 km/s
  • Aphelion Distance: 20.99 AU
  • Perihelion Distance: 1.59 AU

Orbit Simulation

Sky Map

The position of 38P/Stephan-Oterma 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.