function computeTdbMinusTtSpice(daysSinceJ2000InTerrestrialTime) {
  /* STK Comments ------------------------------------------------------
   * This function uses constants designed to be consistent with
   * the SPICE Toolkit from JPL version N0051 (unitim.c)
   * M0 = 6.239996
   * M0Dot = 1.99096871e-7 rad/s = 0.01720197 rad/d
   * EARTH_ECC = 1.671e-2
   * TDB_AMPL = 1.657e-3 secs
   *--------------------------------------------------------------------*/

  //* Values taken as specified in STK Comments except: 0.01720197 rad/day = 1.99096871e-7 rad/sec
  //* Here we use the more precise value taken from the SPICE value 1.99096871e-7 rad/sec converted to rad/day
  //* All other constants are consistent with the SPICE implementation of the TDB conversion
  //* except where we treat the independent time parameter to be in TT instead of TDB.
  //* This is an approximation made to facilitate performance due to the higher prevalance of
  //* the TT2TDB conversion over TDB2TT in order to avoid having to iterate when converting to TDB for the JPL ephemeris.
  //* Days are used instead of seconds to provide a slight improvement in numerical precision.

  //* For more information see:
  //* http://www.cv.nrao.edu/~rfisher/Ephemerides/times.html#TDB
  //* ftp://ssd.jpl.nasa.gov/pub/eph/planets/ioms/ExplSupplChap8.pdf

  const g = 6.239996 + 0.0172019696544 * daysSinceJ2000InTerrestrialTime;
  return 1.657e-3 * Math.sin(g + 1.671e-2 * Math.sin(g));
}
Contains functions for finding the Cartesian coordinates of the sun and the moon in the
Earth-centered inertial frame.

@namespace Simon1994PlanetaryPositions