# Celestial Bodies
Celestial body definitions including physical properties and rotational elements.
## Supported Bodies
Lox supports the standard NAIF/SPICE body identifiers for:
- Planets (Mercury through Neptune)
- Planetary barycenters
- Natural satellites (major moons)
- The Sun
- Solar system barycenter
## Quick Example
```python
import lox_space as lox
# Create by name or ID
earth = lox.Origin("Earth")
moon = lox.Origin("Moon")
mars = lox.Origin(499) # NAIF ID
# Access properties (returns unit types)
print(f"Earth radius: {earth.mean_radius().to_kilometers():.1f} km")
print(f"Earth GM: {earth.gravitational_parameter().to_km3_per_s2():.6e} km³/s²")
# Rotational elements at a given epoch
et = 0.0 # Ephemeris time (seconds from J2000)
ra, dec, w = earth.rotational_elements(et)
print(f"RA: {ra.to_degrees():.2f} deg")
```
---
::: lox_space.Origin
options:
show_source: false