Key Facts

  • Categorized as a Amor-class Asteroid
  • Comparable in size to the Golden Gate Bridge (0.90 km diameter)
  • Will pass within 14,719,683 km of Earth in 2179
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation


Seneca is a small asteroid whose orbit approaches the orbit of Earth but does not cross it. NASA JPL has classified Seneca 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.

Seneca orbits the sun every 1,470 days (4.02 years), coming as close as 1.09 AU and reaching as far as 3.96 AU from the sun. Seneca is about 0.9 kilometers in diameter, making it larger than ~97% of asteroids but small compared to large asteroids, comparable in size to the Golden Gate Bridge.

The rotation of Seneca has been observed. It completes a rotation on its axis every 8.00 hours.

Close Approaches

Seneca's orbit is 0.14 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.

Seneca has 1 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
March 14, 2179 14,719,683 13.254

Images and Observations

Seneca's orbit is determined by observations dating back to Feb. 17, 1978. It was last officially observed on Sept. 18, 2022. The IAU Minor Planet Center records 83 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 Seneca:



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.528 AU
  • Eccentricity: 0.5681
  • Inclination: 14.54°
  • Longitude of Ascending Node: 167.09°
  • Argument of Periapsis: 38.02°
  • Mean Anomaly: 175.19°

Physical Characteristics

  • Diameter: 0.90000 km
  • Magnitude: 17.48
  • Albedo: 0.21
  • Spectral type (Tholen): S

Derived Characteristics

  • Orbit Period: 1,470 days (4.02 years)
  • Avg. Orbit Speed: 18.71 km/s
  • Aphelion Distance: 3.96 AU
  • Perihelion Distance: 1.09 AU
  • Rotation Period: 8.00 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of Seneca 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 Seneca 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.