Key Facts

Overview

Gretia is a large asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified Gretia as potentially hazardous because its orbit does not bring it close to Earth.

Gretia orbits the sun every 1,720 days (4.71 years), coming as close as 2.26 AU and reaching as far as 3.35 AU from the sun. Gretia is about 32.4 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the city of New York.

The rotation of Gretia has been observed. It completes a rotation on its axis every 5.78 hours.

Gretia's spectral type None (Tholen) / Sr (SMASSII) indicates that it is likely to contain and .

No Close Approaches

Gretia's orbit is 1.27 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

Gretia's orbit is determined by observations dating back to Aug. 27, 1922. It was last officially observed on July 3, 2023. The IAU Minor Planet Center records 4,591 observations used to determine its orbit.

Scientists have been able to determine this object's shape:

View asteroid Gretia in 3D.

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 Gretia:

References

Search

   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.805 AU
  • Eccentricity: 0.1954
  • Inclination: 9.09°
  • Longitude of Ascending Node: 314.16°
  • Argument of Periapsis: 55.21°
  • Mean Anomaly: 167.46°

Physical Characteristics

  • Diameter: 32.44900 km
  • Magnitude: 9.57
  • Albedo: 0.421
  • Spectral type (SMASS): Sr

Derived Characteristics

  • Orbit Period: 1,720 days (4.71 years)
  • Avg. Orbit Speed: 17.74 km/s
  • Aphelion Distance: 3.35 AU
  • Perihelion Distance: 2.26 AU
  • Rotation Period: 5.78 hours
  • Approx. Composition: and .

Map Comparison

Click to load map

Orbit Simulation

Sky Map

The position of Gretia 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.