Key Facts


C/2012 H2 (McNaught) is a large comet with a medium-length orbit that is highly inclined to the ecliptic plane of the solar system. NASA JPL has not classified McNaught as potentially hazardous because its orbit does not bring it close to Earth.

McNaught orbits the sun every 23,700 days (64.89 years), coming as close as 1.72 AU and reaching as far as 30.56 AU from the sun. Its orbit is highly elliptical. Based on its brightness and the way it reflects light, McNaught is probably between 2658.000 to 5943.469 kilometers in diameter, making it the largest asteroid/dwarf planet, very roughly comparable in size to the U.S. state of Alaska.

No Close Approaches

McNaught's orbit is 1.10 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

McNaught's orbit is determined by observations dating back to April 29, 2012. It was last officially observed on July 16, 2012. The IAU Minor Planet Center records 40 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 McNaught:



   or view a random object

Orbital Elements

  • Epoch: 2456065.5 JD
  • Semi-major axis: 16.14 AU
  • Eccentricity: 0.8936
  • Inclination: 92.84°
  • Longitude of Ascending Node: 184.14°
  • Argument of Periapsis: 295.9°
  • Mean Anomaly: 0.22°

Physical Characteristics

  • Diameter: ~3431.463 km
  • Magnitude: 15.7

Derived Characteristics

  • Orbit Period: 23,700 days (64.89 years)
  • Avg. Orbit Speed: 7.41 km/s
  • Aphelion Distance: 30.56 AU
  • Perihelion Distance: 1.72 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of C/2012 H2 (McNaught) 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.