Key Facts


ISON is a mid-sized asteroid with an orbit between Jupiter and Neptune. NASA JPL has not classified ISON as potentially hazardous because its orbit does not bring it close to Earth.

ISON orbits the sun every 5,010 days (13.72 years), coming as close as 2.73 AU and reaching as far as 8.73 AU from the sun. Based on its brightness and the way it reflects light, ISON is probably between 3.669 to 8.204 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the San Francisco Bay.

No Close Approaches

ISON's orbit is 1.83 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

ISON's orbit is determined by observations dating back to Oct. 29, 2008. It was last officially observed on July 28, 2019. The IAU Minor Planet Center records 109 observations used to determine its orbit.

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 ISON:



   or view a random object

Orbital Elements

  • Epoch: 2459396.5 JD
  • Semi-major axis: 5.731 AU
  • Eccentricity: 0.524
  • Inclination: 19.98°
  • Longitude of Ascending Node: 219.98°
  • Argument of Periapsis: 268.4°
  • Mean Anomaly: 259.96°

Physical Characteristics

  • Diameter: ~4.737 km
  • Magnitude: 14.3

Derived Characteristics

  • Orbit Period: 5,010 days (13.72 years)
  • Avg. Orbit Speed: 12.44 km/s
  • Aphelion Distance: 8.73 AU
  • Perihelion Distance: 2.73 AU

Map Comparison

Click to load map

Orbit Simulation

Sky Map

The position of ISON 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 ISON 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.