Key Facts


C/2016 Q4 (Kowalski) is a large comet whose orbit is approximately between Jupiter and Neptune. NASA JPL has not classified Kowalski as potentially hazardous because its orbit does not bring it close to Earth.

Kowalski orbits the sun every 25,100 days (68.72 years), coming as close as 7.08 AU and reaching as far as 26.50 AU from the sun. Based on its brightness and the way it reflects light, Kowalski 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

Kowalski's orbit is 6.09 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

Kowalski's orbit is determined by observations dating back to July 11, 2016. It was last officially observed on Nov. 19, 2016. The IAU Minor Planet Center records 81 observations used to determine its orbit.

Accessibility and Exploration

This comet is not considered a viable target for human exploration by the NHATS study.



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Orbital Elements

  • Epoch: 2457635.5 JD
  • Semi-major axis: 16.79 AU
  • Eccentricity: 0.5781
  • Inclination: 7.26°
  • Longitude of Ascending Node: 271.33°
  • Argument of Periapsis: 99.48°
  • Mean Anomaly: 352.68°

Physical Characteristics

  • Diameter: ~3431.463 km
  • Magnitude: 7.0

Derived Characteristics

  • Orbit Period: 25,100 days (68.72 years)
  • Avg. Orbit Speed: 7.28 km/s
  • Aphelion Distance: 26.50 AU
  • Perihelion Distance: 7.08 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of C/2016 Q4 (Kowalski) 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.