Key Facts


111P/Helin-Roman-Crockett is a mid-sized comet whose orbit brings it closer to the sun than Jupiter. NASA JPL has not classified 111P/Helin-Roman-Crockett as potentially hazardous because its orbit does not bring it close to Earth.

111P/Helin-Roman-Crockett orbits the sun every 3,100 days (8.49 years), coming as close as 3.70 AU and reaching as far as 4.62 AU from the sun. 111P/Helin-Roman-Crockett is about 1.2 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the U.S. Pentagon.

No Close Approaches

111P/Helin-Roman-Crockett's orbit is 2.72 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

111P/Helin-Roman-Crockett's orbit is determined by observations dating back to Jan. 3, 1989. It was last officially observed on Dec. 21, 2012. The IAU Minor Planet Center records 137 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 111P/Helin-Roman-Crockett:



   or view a random object

Orbital Elements

  • Epoch: 2456320.5 JD
  • Semi-major axis: 4.16 AU
  • Eccentricity: 0.1096
  • Inclination: 4.23°
  • Longitude of Ascending Node: 89.79°
  • Argument of Periapsis: 3.38°
  • Mean Anomaly: 359.69°

Physical Characteristics

  • Diameter: 1.20000 km
  • Magnitude: 8.4

Derived Characteristics

  • Orbit Period: 3,100 days (8.49 years)
  • Avg. Orbit Speed: 14.60 km/s
  • Aphelion Distance: 4.62 AU
  • Perihelion Distance: 3.70 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 111P/Helin-Roman-Crockett 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 111P/Helin-Roman-Crockett 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.