Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to the U.S. Pentagon (1.30 km diameter)
  • Will pass within 22,078,901 km of Earth in 2031
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation


Summanus is a mid-sized asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified Summanus as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.

Summanus orbits the sun every 812 days (2.22 years), coming as close as 0.90 AU and reaching as far as 2.51 AU from the sun. Summanus is about 1.3 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the U.S. Pentagon.

The rotation of Summanus has been observed. It completes a rotation on its axis every 7.37 hours.

Close Approaches

Summanus's orbit is 0.07 AU from Earth's orbit at its closest point. This means that there is a wide berth between this asteroid and Earth at all times.

Summanus has 5 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
March 20, 2031 22,078,901 17.472
March 1, 2120 29,864,466 11.493
March 5, 2140 21,658,179 12.281
March 6, 2160 19,992,280 12.458
March 4, 2180 23,498,981 12.099

Images and Observations

Summanus's orbit is determined by observations dating back to Sept. 25, 1990. It was last officially observed on March 1, 2022. The IAU Minor Planet Center records 380 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 Summanus:



   or view a random object

Orbital Elements

  • Epoch: 2459600.5 JD
  • Semi-major axis: 1.703 AU
  • Eccentricity: 0.4744
  • Inclination: 19.43°
  • Longitude of Ascending Node: 359.79°
  • Argument of Periapsis: 116.23°
  • Mean Anomaly: 335.91°

Physical Characteristics

  • Diameter: 1.29800 km
  • Magnitude: 18.52
  • Albedo: 0.033

Derived Characteristics

  • Orbit Period: 812 days (2.22 years)
  • Avg. Orbit Speed: 22.82 km/s
  • Aphelion Distance: 2.51 AU
  • Perihelion Distance: 0.90 AU
  • Rotation Period: 7.37 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of Summanus 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 Summanus 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.