The widely heralded and remarkable   progress in cosmology 
leading to  the emergence of a  'standard cosmological model’ has relied on  
certain key assumptions at various levels.  Recent cosmological observations,
in particular, the exquisite   observations  of the Cosmic  Microwave 
Background CMB anisotropy by Planck now do allow us to directly query these
assumptions. I dwell on the enigmatic  Cosmic Hemispherical Anisotropy that  
poses a challenge to the Cosmological principle that lies  at the heart of modern 
cosmology.