NAME: 
  ssgeom
 PURPOSE: 
  Compute Sun and Earth distance and phase angle for solar system object.
 DESCRIPTION:
 CATEGORY:
  Astronomy
 CALLING SEQUENCE:
  ssgeom,ephemeris,sun,earth,phang,elong
 INPUTS:
  ephemeris - 8 by N array as returned from codes 20-22 of EPHEM
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  sun   - Object to Sun distance in AU.
  earth - Object to Earth distance in AU.
  phang - Sun - Object - Earth angle in degrees.
  elong - Object - Earth - Sun angle in degrees.
  kscale - sky-plane scale at the object, km/arcsec
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  93/10/28, Written by Marc W. Buie, Lowell Observatory
  94/08/05, MWB, fixed bug in calculation of ELONG
  2010/08/20, MWB, minor tweak to help eliminate spurious dimensions of;
                   returned information.
  2021/03/04, MWB, added KSCALE output