code: def load_constants():
      
      
      # The universal gravitational constant
      # https://en.wikipedia.org/wiki/Gravitational_constant
      G: float = 6.67408E-11
      
      # The names of the celestial bodies
      body_name = \
          ['sun',
           'moon',
           'mercury',
           'venus',
           'earth',
           'mars',
           'jupiter',
           'saturn',
           'uranus',
           'neptune']
      
      # The mass of the celestial bodies
      # https://en.wikipedia.org/wiki/Earth_mass
      mass_earth: float = 5.9722E24
      mass: Dict[str, float]  = \
          {'sun': mass_earth * 332946.0487,
           'moon' : mass_earth * 0.012300037,
           'mercury': mass_earth * 0.0553,
           'venus': mass_earth * 0.815, 
           'earth': mass_earth * 1.0000,
           'mars': mass_earth * 0.107,
           'jupiter': mass_earth * 317.8,
           'saturn': mass_earth * 95.2,
           'uranus': mass_earth * 14.5,
           'neptune': mass_earth * 17.1,
           }
      
      # The radii of the celestial bodiea
      # https://nineplanets.org/data1.html
      radius: Dict[str, float] = \
      {'sun': 695000e3,
       'moon': 1738e3,
       'mercury': 2440e3,
       'venus': 6052e3,
       'earth': 6378e3,
       'mars': 3397e3,
       'jupiter': 71492e3,
       'saturn': 60268e3,
       'uranus': 35559e3,
       'neptune': 24766e3     
       }
  
      return G, body_name, mass, radius
docs: Load physical constants to simulate the earth-sun system