Use a JPL ephemeris to predict planet positions

 This package can load and use a Jet Propulsion Laboratory (JPL)
 ephemeris for predicting the position and velocity of a planet or other
 Solar System body. It currently supports binary SPK files (extension
 ".bsp") like those distributed by the Jet Propulsion Laboratory
 that are:
 .
  * Type 2 - positions stored as Chebyshev polynomials, with velocity
    derived by computing their derivative.
  * Type 3 - positions and velocities both stored explicitly as
    Chebyshev polynomials.
  * Type 9 - a series of discrete positions and velocities, with
    separate timestamps that do not need to be equally spaced. Currently
    there is only support for linear interpolation: for Type 9 ephemerides
    of polynomial degree 1, not of any higher degrees.
 .
 Even if an ephemeris isn't one of the above types, it is still possible
 to use jplephem to read its text comment and list the segments inside.