Key Facts
- Categorized as a Main-belt Asteroid
- Comparable in size to the U.S. state of Delaware (81.24 km diameter)
- Not a Near Earth Object
- Not a Potentially Hazardous Object
- See orbit simulation
Overview
Una is a large asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified Una as potentially hazardous because its orbit does not bring it close to Earth.
Una orbits the sun every 1,650 days (4.52 years), coming as close as 2.55 AU and reaching as far as 2.91 AU from the sun. Una is about 81.2 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the U.S. state of Delaware.
The rotation of Una has been observed. It completes a rotation on its axis every 11.03 hours.
Una's spectral type CX (Tholen) / C (SMASSII) indicates that it is likely to contain water, iron, nickel, cobalt, nitrogen, and ammonia.
No Close Approaches
Una's orbit is 1.56 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
Una's orbit is determined by observations dating back to Feb. 25, 1876. It was last officially observed on Dec. 17, 2022. The IAU Minor Planet Center records 4,201 observations used to determine its orbit.
Scientists have been able to determine this object's shape:
View asteroid Una 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 Una:References
Search
or view a random objectOrbital Elements
- Epoch: 2460200.5 JD
- Semi-major axis: 2.729 AU
- Eccentricity: 0.0667
- Inclination: 3.82°
- Longitude of Ascending Node: 8.57°
- Argument of Periapsis: 50.21°
- Mean Anomaly: 356.0°
Physical Characteristics
- Diameter: 81.24000 km
- Magnitude: 9.15
- Albedo: 0.0625
- Spectral type (Tholen): CX
- Spectral type (SMASS): C
Derived Characteristics
- Orbit Period: 1,650 days (4.52 years)
- Avg. Orbit Speed: 17.99 km/s
- Aphelion Distance: 2.91 AU
- Perihelion Distance: 2.55 AU
- Rotation Period: 11.03 hours
- Approx. Composition: water, iron, nickel, cobalt, nitrogen, and ammonia.
Map Comparison
Orbit Simulation
Sky Map
The position of Una 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.