Key Facts

  • Categorized as a Main-belt Asteroid
  • Comparable in size to the U.S. state of Connecticut (139.59 km diameter)
  • Not a Near Earth Object
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

Melpomene is a very large asteroid circling the sun between Mars and Jupiter, inside the main asteroid belt. NASA JPL does not treat Melpomene as potentially hazardous, because its orbit never carries it near Earth.

One lap around the sun takes Melpomene 1,270 days (3.48 years). Over that circuit it swings between 1.79 AU and 2.8 AU from the sun, travelling at an average of 19.67 km/s. At 139.6 kilometers across, Melpomene is bigger than 99% of known asteroids — roughly the size of the U.S. state of Connecticut.

Melpomene has been watched long enough to time its spin: one full turn on its axis takes 11.57 hours.

Melpomene is classed as S on the Tholen scale, S on SMASSII.

No Close Approaches

At their nearest, the orbits of Melpomene and Earth stay 0.81 AU apart. That is a comfortable margin, and it holds at every point in the orbit.

Orbital simulations run by NASA JPL's CNEOS turn up no close approaches to Earth.

Images and Observations

The orbit of Melpomene is pinned down by sightings going back to June 29, 1852, the most recent officially logged on Sept. 9, 2022. The IAU Minor Planet Center holds 6,122 observations behind that solution.

Accessibility and Exploration

The NHATS study does not rate Melpomene as a realistic destination for a crewed mission.

Similar Objects

These objects follow orbits with much the same shape and tilt as Melpomene:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.296 AU
  • Eccentricity: 0.2184
  • Inclination: 10.13°
  • Longitude of Ascending Node: 150.36°
  • Argument of Periapsis: 228.15°
  • Mean Anomaly: 0.4°

Physical Characteristics

  • Diameter: 139.59400 km
  • Magnitude: 6.34
  • Albedo: 0.181
  • Spectral type (Tholen): S
  • Spectral type (SMASS): S

Derived Characteristics

  • Orbit Period: 1,270 days (3.48 years)
  • Avg. Orbit Speed: 19.67 km/s
  • Aphelion Distance: 2.8 AU
  • Perihelion Distance: 1.79 AU
  • Rotation Period: 11.57 hours

Map Comparison

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Orbit Simulation

Sky Map

A ◯ pink circle marks where Melpomene sits. It may fall outside your current field of view — use the controls below to change the position, location and time.