Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to Mount Everest (1.65 km diameter)
  • Will pass within 6,641,824 km of Earth in 2038
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation


Tantalus is a mid-sized asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified Tantalus as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

Tantalus orbits the sun every 535 days (1.46 years), coming as close as 0.90 AU and reaching as far as 1.68 AU from the sun. Tantalus is about 1.6 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to Mount Everest.

The rotation of Tantalus has been observed. It completes a rotation on its axis every 2.38 hours.

Tantalus's spectral type None (Tholen) / Q (SMASSII) indicates that it is likely to contain .

Close Approaches

Tantalus's orbit is 0.04 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.

Tantalus has 8 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Dec. 27, 2038 6,641,824 33.430
Dec. 23, 2060 14,830,577 34.283
Jan. 2, 2080 26,917,582 32.617
Dec. 29, 2101 10,539,033 33.161
Dec. 27, 2123 7,796,052 33.816
Dec. 22, 2145 23,621,909 34.942
Dec. 31, 2164 17,268,469 32.911
Dec. 28, 2186 5,529,368 33.613

Images and Observations

Tantalus's orbit is determined by observations dating back to Dec. 30, 1975. It was last officially observed on July 23, 2023. The IAU Minor Planet Center records 1,647 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 Tantalus:



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.29 AU
  • Eccentricity: 0.2993
  • Inclination: 64.0°
  • Longitude of Ascending Node: 94.35°
  • Argument of Periapsis: 61.52°
  • Mean Anomaly: 169.2°

Physical Characteristics

  • Diameter: 1.64900 km
  • Magnitude: 15.97
  • Albedo: 0.245
  • Spectral type (SMASS): Q

Derived Characteristics

  • Orbit Period: 535 days (1.46 years)
  • Avg. Orbit Speed: 26.23 km/s
  • Aphelion Distance: 1.68 AU
  • Perihelion Distance: 0.90 AU
  • Rotation Period: 2.38 hours
  • Approx. Composition: .

Map Comparison

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Orbit Simulation

Sky Map

The position of Tantalus 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 Tantalus 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.