Asteroid
Near-Earth
Potentially hazardous
Zephyr
12923 Zephyr (1999 GK4)
Where is it now
- Distance from Sun
- 2.005 AU
- True anomaly
- 238.25°
- As of
- 29 August 2026
Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.
Orbital elements
- Semi-major axis
- 1.962 AU
- Eccentricity
- 0.4931
- Inclination
- 5.31°
- Orbital period
- 2.75 years
- Perihelion
- 0.994 AU
- Aphelion
- 2.929 AU
- Longitude of ascending node
- 168.07°
- Argument of periapsis
- 147.23°
- Epoch · J2000
- 2461200.5
Physical properties
- Mean radius
- 1.03 km
- Rotation period
- 3.89 hours
Visual & observation
- Geometric albedo
- 0.199
- Absolute magnitude (H)
- 15.8
- Spectral type
- APO
Discovery & classification
Near-Earth Object
Named
Potentially Hazardous Asteroid